S^3 = 2 x S^3

???Confused

Changing the variables as two Different Cubes

a^3 = 2 b^3 ( A is twice that of B)

a = ? ??

a x a^2 = 2 x b^3

a = 2 x b^3 /a^2 ?????

Next? ?

Is my thought process is right??

]]>

S^3 = 2 x S^3

???Confused

Changing the variables as two Different Cubes

a^3 = 2 b^3 ( A is twice that of B)

a = ? ??

a x a^2 = 2 x b^3

a = 2 x b^3 /a^2 ?????

Next? ?

Is my thought process is right??]]>

We should concentrate on non-water component as not changing in number

1% of non-water ---> 2% of non-water

doubling the concentration that can be only if we halve the total weight, so 100/2=50

Algebraic:

(99-x/100-x)*100=98

100=2x

x=50, so 100-50=50

B

]]>

We should concentrate on non-water component as not changing in number

1% of non-water ---> 2% of non-water

doubling the concentration that can be only if we halve the total weight, so 100/2=50

Algebraic:

(99-x/100-x)*100=98

100=2x

x=50, so 100-50=50

B]]>

40----------25----20

15x=5y

x/y=5/15=1/3, so 1 part of 40% sol should be added 3 part of 20%.

So 150*3=450

E

]]>

40----------25----20

15x=5y

x/y=5/15=1/3, so 1 part of 40% sol should be added 3 part of 20%.

So 150*3=450

E]]>

In the rectangular coordinate system, are the points (r,s) and (u,v) equidistant from the origin?

(1) r + s = 1

(2) u = 1-r and v = 1-s

Bunnel, can you please help me to get the quick solution to this problem ?

Merging topics. Please refer to the discussion above.

]]>

In the rectangular coordinate system, are the points (r,s) and (u,v) equidistant from the origin?

(1) r + s = 1

(2) u = 1-r and v = 1-s

Bunnel, can you please help me to get the quick solution to this problem ?

Merging topics. Please refer to the discussion above.]]>

A)9

B) 10

C) 12

D) 15

E) 8

Source; 4gmat

]]>

A)9

B) 10

C) 12

D) 15

E) 8

Source; 4gmat]]>

Bunuel wrote:

SOLUTION

If n + k = m, what is the value of k ?

n + k = m --> k=m-n=?

(1) n = 10 --> k=m-n=m-10. Not sufficient.

(2) m + 10 = n --> m-n=10, so k=10. Sufficient.

Answer: B.

If n + k = m, what is the value of k ?

n + k = m --> k=m-n=?

(1) n = 10 --> k=m-n=m-10. Not sufficient.

(2) m + 10 = n --> m-n=10, so k=10. Sufficient.

Answer: B.

Bunuel,

(2) m + 10 = n --> m-n=10, so k=10. Sufficient.

hy it isn't m+10=n --> m=n-10 --> m-n=-10?

Thanks!

...

]]>

Bunuel wrote:

SOLUTION

If n + k = m, what is the value of k ?

n + k = m --> k=m-n=?

(1) n = 10 --> k=m-n=m-10. Not sufficient.

(2) m + 10 = n --> m-n=10, so k=10. Sufficient.

Answer: B.

If n + k = m, what is the value of k ?

n + k = m --> k=m-n=?

(1) n = 10 --> k=m-n=m-10. Not sufficient.

(2) m + 10 = n --> m-n=10, so k=10. Sufficient.

Answer: B.

Bunuel,

(2) m + 10 = n --> m-n=10, so k=10. Sufficient.

hy it isn't m+10=n --> m=n-10 --> m-n=-10?

Thanks!

...]]>

:) Shudn the answer be A?

The question asks which of the following is impossible. It's not possible mean not to change so the answer is B.

]]>

:) Shudn the answer be A?

The question asks which of the following is impossible. It's not possible mean not to change so the answer is B.]]>

A) $60,000

B) $16,000

C) $15,000

D) $14,000

E) $30,000

Source: 4gmat

]]>

A) $60,000

B) $16,000

C) $15,000

D) $14,000

E) $30,000

Source: 4gmat]]>

Bumping up and asking for a different explanation. So, according to MGMAT's explanation, they used a table method to solve this question - which is not very helpful. Could someone explain in a simpler way to solve this using the table method? Also, isn't there "one ring to rule them all" for this type of questions?

p.s.: Sadly,I can't attach a screen grab of their explanation to this reply

A feed store sells two varieties of birdseed: Brand A, which is 40% millet and 60% sunflower,

...

]]>

Bumping up and asking for a different explanation. So, according to MGMAT's explanation, they used a table method to solve this question - which is not very helpful. Could someone explain in a simpler way to solve this using the table method? Also, isn't there "one ring to rule them all" for this type of questions?

p.s.: Sadly,I can't attach a screen grab of their explanation to this reply

A feed store sells two varieties of birdseed: Brand A, which is 40% millet and 60% sunflower,

...]]>

]]>

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.

]]>

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.]]>

Is the positive two-digit integer N less than 40 ?

(1) The units digit of N is 6 more than the tens digit.

(2) N is 4 less than 4 times the units digit.

D.

1) let N = ab

=> b = a+6

b can maximum be 9, in which case a would be 3 (N = 39 max)

so N < 40 - Yes.

sufficient.

2) let N = ab

=> 10a+b - 4 = 4b

=> 10a-3b = 4

(a,b) = (1,2) is the only valid solution

so N < 40 - Yes

sufficient.

]]>

Is the positive two-digit integer N less than 40 ?

(1) The units digit of N is 6 more than the tens digit.

(2) N is 4 less than 4 times the units digit.

D.

1) let N = ab

=> b = a+6

b can maximum be 9, in which case a would be 3 (N = 39 max)

so N < 40 - Yes.

sufficient.

2) let N = ab

=> 10a+b - 4 = 4b

=> 10a-3b = 4

(a,b) = (1,2) is the only valid solution

so N < 40 - Yes

sufficient.]]>

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.

]]>

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.]]>

Official Solution:

If functionf(x) satisfiesf(x) = f(x^2) for allx , which of the following must be true?

A. f(4) = f(2)f(2)

B. f(16) - f(-2) = 0

C. f(-2) + f(4) = 0

D. f(3) = 3f(3)

E. f(0) = 0

We are told that some functionf(x) has the following propertyf(x) = f(x^2) for all values ofx . Note

...

]]>

Official Solution:

If functionf(x) satisfiesf(x) = f(x^2) for allx , which of the following must be true?

A. f(4) = f(2)f(2)

B. f(16) - f(-2) = 0

C. f(-2) + f(4) = 0

D. f(3) = 3f(3)

E. f(0) = 0

We are told that some functionf(x) has the following propertyf(x) = f(x^2) for all values ofx . Note

...]]>

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.

]]>

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.]]>

The population of a bacteria colony doubles every day. If it was started 9 days ago with 2 bacteria and each bacteria lives for 12 days, how large is the colony today?

A. 512

B. 768

C. 1024

D. 2048

E. 4096

This question was a sitter, still i got this wrong not because I didn't know the concepts well, but because I did a silly mistake. Since the information provided is of 9 days ago, I calculated the answer for 9 days itself. The calculation should be done for n+1 days.

It started with 2 bacteria,

...

]]>

The population of a bacteria colony doubles every day. If it was started 9 days ago with 2 bacteria and each bacteria lives for 12 days, how large is the colony today?

A. 512

B. 768

C. 1024

D. 2048

E. 4096

This question was a sitter, still i got this wrong not because I didn't know the concepts well, but because I did a silly mistake. Since the information provided is of 9 days ago, I calculated the answer for 9 days itself. The calculation should be done for n+1 days.

It started with 2 bacteria,

...]]>

If {-\frac{1}{3}} \le {x} \le {-\frac{1}{5}} and {-\frac{1}{2}} \le {y} \le {-\frac{1}{4}}, what is the least value of x^2*y possible?

A. -\frac{1}{100}

B. -\frac{1}{50}

C. -\frac{1}{36}

D. -\frac{1}{18}

E. -\frac{1}{6}

I got this question wrong in the test, because of a silly mistake, but now when I look at my mistake, I laugh. Anyways, here's the explanation

If the value has to be least, possible, the value must be negative and the value

...

]]>

If {-\frac{1}{3}} \le {x} \le {-\frac{1}{5}} and {-\frac{1}{2}} \le {y} \le {-\frac{1}{4}}, what is the least value of x^2*y possible?

A. -\frac{1}{100}

B. -\frac{1}{50}

C. -\frac{1}{36}

D. -\frac{1}{18}

E. -\frac{1}{6}

I got this question wrong in the test, because of a silly mistake, but now when I look at my mistake, I laugh. Anyways, here's the explanation

If the value has to be least, possible, the value must be negative and the value

...]]>

If a, b, and c are integers and a \lt b \lt c, are a, b, and c consecutive integers?

(1) The median of {a!, b!, c!} is an odd number.

(2) c! is a prime number.

I got this question wrong in the test, because I didn't pay special attention to every detail given in the question.

Here's the right solution :

1. The median of a! b! c! is an odd number, it means that b is either 0 or 1. Since we can have a!, it means that a is greater than or equal to 0. We also know that a < b < c, so a

...

]]>

If a, b, and c are integers and a \lt b \lt c, are a, b, and c consecutive integers?

(1) The median of {a!, b!, c!} is an odd number.

(2) c! is a prime number.

I got this question wrong in the test, because I didn't pay special attention to every detail given in the question.

Here's the right solution :

1. The median of a! b! c! is an odd number, it means that b is either 0 or 1. Since we can have a!, it means that a is greater than or equal to 0. We also know that a < b < c, so a

...]]>

If x=\sqrt[4]{x^3+6x^2}, then the sum of all possible solutions for x is:

A. -2

B. 0

C. 1

D. 3

E. 5

I got this question wrong in the test. So, solving it here for a better understanding.

Basically this question tests one concept i.e.\sqrt{x^2} is x and not -x.

Solving the equation, x^4= x^3+6x^2

=> x^4-x^3-6x^2=0

x^2(x^2-x-6)=0x=0,3,-2

As mentioned earlier, \sqrt{x^2} is x and not -x, the value -2 is discarded.

Thus the two values are 3 and 0

SO, the sum = 3

...

]]>

If x=\sqrt[4]{x^3+6x^2}, then the sum of all possible solutions for x is:

A. -2

B. 0

C. 1

D. 3

E. 5

I got this question wrong in the test. So, solving it here for a better understanding.

Basically this question tests one concept i.e.\sqrt{x^2} is x and not -x.

Solving the equation, x^4= x^3+6x^2

=> x^4-x^3-6x^2=0

x^2(x^2-x-6)=0x=0,3,-2

As mentioned earlier, \sqrt{x^2} is x and not -x, the value -2 is discarded.

Thus the two values are 3 and 0

SO, the sum = 3

...]]>

(11*x)/y seconds

]]>

(11*x)/y seconds]]>

This method might help in the worst case.

]]>

This method might help in the worst case.]]>

t=3.5

substituting the value in 80t, we get the distance as 280

]]>

t=3.5

substituting the value in 80t, we get the distance as 280]]>

Tough and Tricky questions: Exponents.

If a and b are positive integers and x = 4^a and y = 9^b, which of the following is a possible units digit of xy?

A. 1

B. 4

C. 5

D. 7

E. 8

unit digit of x=4^a will either be 4 or 6 (4 if a is odd and 6 if a is even)

and unit digit of y=9^b will either be 1 or 9 (9 if b is odd and 1 if b is even)

now we have total 4 possible combinations

1) a=odd, b=odd

unit digit=9*4=6

2)a=odd, b=even

unit digit=4*1=4

3) a=even,b=odd

unit digit=6*9=4

4)a=even, b=even

unit

...

]]>

Tough and Tricky questions: Exponents.

If a and b are positive integers and x = 4^a and y = 9^b, which of the following is a possible units digit of xy?

A. 1

B. 4

C. 5

D. 7

E. 8

unit digit of x=4^a will either be 4 or 6 (4 if a is odd and 6 if a is even)

and unit digit of y=9^b will either be 1 or 9 (9 if b is odd and 1 if b is even)

now we have total 4 possible combinations

1) a=odd, b=odd

unit digit=9*4=6

2)a=odd, b=even

unit digit=4*1=4

3) a=even,b=odd

unit digit=6*9=4

4)a=even, b=even

unit

...]]>

Tough and Tricky questions: Properties of Numbers.

If y is divisible by the square of an even prime number and x is the actual square of an even prime number, then what is the units digit of x^y?

A. 0

B. 2

C. 4

D. 6

E. 8

even prime number is 2, and its square=4

thus y=4k ;k=1,2,3,,,,,

and x=4

x^y=4^4k; unit digit of 4 is 4 if its power is odd, else it is 6. now since 4k will always be even. therefore the unit digit of 4^4k will always be 6.

...

]]>

Tough and Tricky questions: Properties of Numbers.

If y is divisible by the square of an even prime number and x is the actual square of an even prime number, then what is the units digit of x^y?

A. 0

B. 2

C. 4

D. 6

E. 8

even prime number is 2, and its square=4

thus y=4k ;k=1,2,3,,,,,

and x=4

x^y=4^4k; unit digit of 4 is 4 if its power is odd, else it is 6. now since 4k will always be even. therefore the unit digit of 4^4k will always be 6.

...]]>

Marcab wrote:

If a is non-negative, is x^2 + y^2 > 4a ?

(1) (x + y)^2 = 9a

(2) (x - y)^2 = a

Source: Jamboree

I am not convinced with the OA.

(1) (x + y)^2 = 9a

(2) (x - y)^2 = a

Source: Jamboree

I am not convinced with the OA.

If a is non-negative, is x^2 + y^2 > 4a ?

(1) (x + y)^2 = 9a --> x^2+2xy+y^2=9a. Clearly insufficient.

(2) (x – y)^2 = a --> x^2-2xy+y^2=a. Clearly insufficient.

(1)+(2) Add them up 2(x^2+y^2)=10a --> x^2+y^2=5a. Also insufficient as x, y, and a could be 0 and x^2 + y^2 > 4a won't be true, as LHS and RHS would be in that case equal

...

]]>

Marcab wrote:

If a is non-negative, is x^2 + y^2 > 4a ?

(1) (x + y)^2 = 9a

(2) (x - y)^2 = a

Source: Jamboree

I am not convinced with the OA.

(1) (x + y)^2 = 9a

(2) (x - y)^2 = a

Source: Jamboree

I am not convinced with the OA.

If a is non-negative, is x^2 + y^2 > 4a ?

(1) (x + y)^2 = 9a --> x^2+2xy+y^2=9a. Clearly insufficient.

(2) (x – y)^2 = a --> x^2-2xy+y^2=a. Clearly insufficient.

(1)+(2) Add them up 2(x^2+y^2)=10a --> x^2+y^2=5a. Also insufficient as x, y, and a could be 0 and x^2 + y^2 > 4a won't be true, as LHS and RHS would be in that case equal

...]]>

Bunuel wrote:

Tough and Tricky questions: Remainders.

1^1 + 2^2 + 3^3 + ... + 10^10 is divided by 5. What is the remainder?

(A) 0

(B) 1

(C) 2

(D) 3

(E) 4

a number is divisible by 5, if its last digit is divisible by 5

let's look into the sum of last digits of each term of the given expression

1^1=1

2^2=4

3^3=7

4^4=6

5^5=5

6^6=6

7^7=3

8^8=6

9^9=9

10^10=0

adding all these numbers we get 47 which gives a remainder of 2 when divided by 5. so answer must be 2.

bunuel, can you please confirm

...

]]>

Bunuel wrote:

Tough and Tricky questions: Remainders.

1^1 + 2^2 + 3^3 + ... + 10^10 is divided by 5. What is the remainder?

(A) 0

(B) 1

(C) 2

(D) 3

(E) 4

a number is divisible by 5, if its last digit is divisible by 5

let's look into the sum of last digits of each term of the given expression

1^1=1

2^2=4

3^3=7

4^4=6

5^5=5

6^6=6

7^7=3

8^8=6

9^9=9

10^10=0

adding all these numbers we get 47 which gives a remainder of 2 when divided by 5. so answer must be 2.

bunuel, can you please confirm

...]]>

In a rectangular coordinate system, if a line passes through the points (-10,-18), (20,22) and (x,2) then what is the value of x?

A) 2

B) 3

C) 4

D) 5

E) 6

Can anyone solve this for me please???

slope of the line m= 22-(-18)/20-(-10)

=4/3

thus its equation is

(y-(-18))=4/3(x-(-10))

3y=4x-14

now since point (x,2) lie on this line, therefore it will satisfy this equation.

6=4x-14

4x=20

x=5

]]>

In a rectangular coordinate system, if a line passes through the points (-10,-18), (20,22) and (x,2) then what is the value of x?

A) 2

B) 3

C) 4

D) 5

E) 6

Can anyone solve this for me please???

slope of the line m= 22-(-18)/20-(-10)

=4/3

thus its equation is

(y-(-18))=4/3(x-(-10))

3y=4x-14

now since point (x,2) lie on this line, therefore it will satisfy this equation.

6=4x-14

4x=20

x=5]]>

Bunuel wrote:

10. If n is not equal to 0, is |n| < 4 ?

(1) n^2 > 16

(2) 1/|n| > n

Question basically asks is -4<n<4 true.

(1) n^2>16 --> n>4 or n<-4, the answer to the question is NO. Sufficient.

(2) 1/|n| > n, this is true for all negative values of n, hence we can not answer the question. Not sufficient.

Answer: A.

(1) n^2 > 16

(2) 1/|n| > n

Question basically asks is -4<n<4 true.

(1) n^2>16 --> n>4 or n<-4, the answer to the question is NO. Sufficient.

(2) 1/|n| > n, this is true for all negative values of n, hence we can not answer the question. Not sufficient.

Answer: A.

hi

m a little confused here. How is A sufficient

isn't n^2>16 ----> n^2-16>0 ---> (N^2-4^2) >0 ----> n+4>0 or n-4>0

...

]]>

Bunuel wrote:

10. If n is not equal to 0, is |n| < 4 ?

(1) n^2 > 16

(2) 1/|n| > n

Question basically asks is -4<n<4 true.

(1) n^2>16 --> n>4 or n<-4, the answer to the question is NO. Sufficient.

(2) 1/|n| > n, this is true for all negative values of n, hence we can not answer the question. Not sufficient.

Answer: A.

(1) n^2 > 16

(2) 1/|n| > n

Question basically asks is -4<n<4 true.

(1) n^2>16 --> n>4 or n<-4, the answer to the question is NO. Sufficient.

(2) 1/|n| > n, this is true for all negative values of n, hence we can not answer the question. Not sufficient.

Answer: A.

hi

m a little confused here. How is A sufficient

isn't n^2>16 ----> n^2-16>0 ---> (N^2-4^2) >0 ----> n+4>0 or n-4>0

...]]>

Tough and Tricky questions: Remainders.

If x and y are positive integers and n = 5^x + 7^(y + 15), what is the units digit of n?

(1) y = 2x – 15

(2) y^2 – 6y + 5 = 0

CheckUnits digits, exponents, remainders problems directory in ourSpecial Questions Directory .

...

]]>

Tough and Tricky questions: Remainders.

If x and y are positive integers and n = 5^x + 7^(y + 15), what is the units digit of n?

(1) y = 2x – 15

(2) y^2 – 6y + 5 = 0

CheckUnits digits, exponents, remainders problems directory in ourSpecial Questions Directory .

...]]>

Tough and Tricky questions: Remainders.

If r, s, and t are all positive integers, what is the remainder of 2^p/10, if p = rst?

(1) s is even

(2) p = 4t

CheckUnits digits, exponents, remainders problems directory in ourSpecial Questions Directory .

...

]]>

Tough and Tricky questions: Remainders.

If r, s, and t are all positive integers, what is the remainder of 2^p/10, if p = rst?

(1) s is even

(2) p = 4t

CheckUnits digits, exponents, remainders problems directory in ourSpecial Questions Directory .

...]]>

Bunuel wrote:

In Garfield School, 250 students participate in debate or student government or both. If 40 of these students participate in both debate and student government, how many of these students do not participate in debate?

Given: {250}={Debate}+{Government}-{40}, (notice that 250 students participate indebate orgovernment orboth , so no need of the group {neither} here).

Question: how many of these students do not participate in debate? Which means how many participate in government

Given: {250}={Debate}+{Government}-{40}, (notice that 250 students participate indebate orgovernment orboth , so no need of the group {neither} here).

Question: how many of these students do not participate in debate? Which means how many participate in government

...

Attachments

Untitled.png [ 6.56 KiB | Viewed 40 times ]

]]>

Bunuel wrote:

In Garfield School, 250 students participate in debate or student government or both. If 40 of these students participate in both debate and student government, how many of these students do not participate in debate?

Given: {250}={Debate}+{Government}-{40}, (notice that 250 students participate indebate orgovernment orboth , so no need of the group {neither} here).

Question: how many of these students do not participate in debate? Which means how many participate in government

Given: {250}={Debate}+{Government}-{40}, (notice that 250 students participate indebate orgovernment orboth , so no need of the group {neither} here).

Question: how many of these students do not participate in debate? Which means how many participate in government

...

Attachments

Untitled.png [ 6.56 KiB | Viewed 40 times ]

]]>

(1) The total age of all the employees in these companies is 600. The question becomes: is 600 \lt 600x? Or is 1 \lt x. We don't know that: if x=1, then the answer is NO but if x \gt 1, then the answer is YES. Not sufficient.

I dont understand why you ruled out Statement 1. We know that x>1 since there is a given ratio for the employees. isnt that sufficient?

We don't know whether x > 1. The ratio could be 3:4:8, which is if x = 1.

]]>

(1) The total age of all the employees in these companies is 600. The question becomes: is 600 \lt 600x? Or is 1 \lt x. We don't know that: if x=1, then the answer is NO but if x \gt 1, then the answer is YES. Not sufficient.

I dont understand why you ruled out Statement 1. We know that x>1 since there is a given ratio for the employees. isnt that sufficient?

We don't know whether x > 1. The ratio could be 3:4:8, which is if x = 1.]]>

I am getting ans as 1/2

we have to find the probability of getting (T,NM,NM)

NM,NM - 5C2=10

and total ways- 6C3=20

therefore - 10/20 =1/2

It should be 4C2: choosing 2 out out of 4 (6 - Tom - Mary).

]]>

I am getting ans as 1/2

we have to find the probability of getting (T,NM,NM)

NM,NM - 5C2=10

and total ways- 6C3=20

therefore - 10/20 =1/2

It should be 4C2: choosing 2 out out of 4 (6 - Tom - Mary).]]>

Bunuel wrote:

Official Solution:

1234@ to be divisible by 5, symbol"@ " should represent either 0 or 5. So the question asks whether@ equals to 0 or 5.

(1)@! is not divisible by 5. @ can be 0, 1, 2, 3, or 4 (note that 0!=1). Not sufficient.

(2)@ is divisible by 9. @ can be 0 or 9 (note that zero is divisible by every integer except zero itself). Not sufficient.

(1)+(2) Intersection of the values for@ from (1) and (2) is@=0 . Sufficient.

Answer:

1234@ to be divisible by 5, symbol"@ " should represent either 0 or 5. So the question asks whether@ equals to 0 or 5.

(1)@! is not divisible by 5. @ can be 0, 1, 2, 3, or 4 (note that 0!=1). Not sufficient.

(2)@ is divisible by 9. @ can be 0 or 9 (note that zero is divisible by every integer except zero itself). Not sufficient.

(1)+(2) Intersection of the values for@ from (1) and (2) is@=0 . Sufficient.

Answer:

...

]]>

Bunuel wrote:

Official Solution:

1234@ to be divisible by 5, symbol"@ " should represent either 0 or 5. So the question asks whether@ equals to 0 or 5.

(1)@! is not divisible by 5. @ can be 0, 1, 2, 3, or 4 (note that 0!=1). Not sufficient.

(2)@ is divisible by 9. @ can be 0 or 9 (note that zero is divisible by every integer except zero itself). Not sufficient.

(1)+(2) Intersection of the values for@ from (1) and (2) is@=0 . Sufficient.

Answer:

1234@ to be divisible by 5, symbol"@ " should represent either 0 or 5. So the question asks whether@ equals to 0 or 5.

(1)@! is not divisible by 5. @ can be 0, 1, 2, 3, or 4 (note that 0!=1). Not sufficient.

(2)@ is divisible by 9. @ can be 0 or 9 (note that zero is divisible by every integer except zero itself). Not sufficient.

(1)+(2) Intersection of the values for@ from (1) and (2) is@=0 . Sufficient.

Answer:

...]]>

8!/(8/4!)^4=2520

]]>

8!/(8/4!)^4=2520]]>

A man sets out to cycle from BBSR to CTC and at the same time another man starts from CTC to BBSR. After passing each other they complete their journeys in 4 and 9 hrs respectively. At what rate does the second man cycle if the first one cycles at 9 km/hr.

A. 4 km/hr

B. 6 km/hr

C. 8 km/hr

D. 9 km/hr

E. can't be determined

You can use the formula or the ratio approach.

Formula:

If two objects A and B start simultaneously from opposite points and, after meeting, reach their destinations in ‘a’

...

]]>

A man sets out to cycle from BBSR to CTC and at the same time another man starts from CTC to BBSR. After passing each other they complete their journeys in 4 and 9 hrs respectively. At what rate does the second man cycle if the first one cycles at 9 km/hr.

A. 4 km/hr

B. 6 km/hr

C. 8 km/hr

D. 9 km/hr

E. can't be determined

You can use the formula or the ratio approach.

Formula:

If two objects A and B start simultaneously from opposite points and, after meeting, reach their destinations in ‘a’

...]]>

...

]]>

...]]>

Units digit

1!=1

2!=2

3!=6

4!=4

5! and above 0

so 6+4+2+1 = 13 or units digit 3. Only answer choice that ends with 3 is B:-)

Bunuel wrote:

Official Solution:

What is1! + 2! + ... + 10! ?

A. 4,037,910

B. 4,037,913

C. 4,037,915

D. 4,037,916

E. 4,037,918

1! + 2! + ... + 10! = 1 + (2! + ... + 10!) = odd + even = odd.

1! + 2! + ... + 10! = 3 + (3! + ... + 10!) = integer divisible by 3.

Among the listed choices we are looking for odd integers

...

]]>

Units digit

1!=1

2!=2

3!=6

4!=4

5! and above 0

so 6+4+2+1 = 13 or units digit 3. Only answer choice that ends with 3 is B:-)

Bunuel wrote:

Official Solution:

What is1! + 2! + ... + 10! ?

A. 4,037,910

B. 4,037,913

C. 4,037,915

D. 4,037,916

E. 4,037,918

1! + 2! + ... + 10! = 1 + (2! + ... + 10!) = odd + even = odd.

1! + 2! + ... + 10! = 3 + (3! + ... + 10!) = integer divisible by 3.

Among the listed choices we are looking for odd integers

...]]>

For the above mentioned question, were the options different? Can you confirm the answer for the same too?

]]>

For the above mentioned question, were the options different? Can you confirm the answer for the same too?]]>

Statement A assumes that there is only 1 team..say the other 2 Italians belong to a team Zeta not mentioned in d question..

It misleads u into picking C or B..

]]>

Statement A assumes that there is only 1 team..say the other 2 Italians belong to a team Zeta not mentioned in d question..

It misleads u into picking C or B..]]>

I found it my self, from other forum. key word in this question is "ANY" sub set.

Sorry for bothering to much

That's why it's important to read the question and solutions carefully.

In my solution here: if-the-mean-of-set-s-does-not-exceed-mean-of-any-subset-of-93565.html#p720756 Crucial word ANY is in bold. Here: ...

]]>

I found it my self, from other forum. key word in this question is "ANY" sub set.

Sorry for bothering to much

That's why it's important to read the question and solutions carefully.

In my solution here: if-the-mean-of-set-s-does-not-exceed-mean-of-any-subset-of-93565.html#p720756 Crucial word ANY is in bold. Here: ...]]>

Hello,

Doesn't the word "recommend" require the usage of the subjunctive form:-

Recommend+that+Subject+Subjunctive form of the verb?

I agree the last sentence is wrong for other reasons as stated in the solution.

However the isnt the usage of the subjunctive form necessary with the word recommend ?

Exactly my query. I came on this thread to post this only, fortunatelyMadhav has already posted it.

Experts, kindly help us in figuring out the above issue.

Request/Recommend is

...

]]>

Hello,

Doesn't the word "recommend" require the usage of the subjunctive form:-

Recommend+that+Subject+Subjunctive form of the verb?

I agree the last sentence is wrong for other reasons as stated in the solution.

However the isnt the usage of the subjunctive form necessary with the word recommend ?

Exactly my query. I came on this thread to post this only, fortunatelyMadhav has already posted it.

Experts, kindly help us in figuring out the above issue.

Request/Recommend is

...]]>

Bunuel wrote:

rpamecha wrote:

SCORE INTERVAL----------------NUMBER OF SCORES

50-59-------------------------- 2

60-69--------------------------10

70-79--------------------------16

80-89--------------------------27

90-99--------------------------18

The table shown above has distribution of test scores. Which score interval contains the median of the 73 scores?

A.60-69

B.70-79

C.80-89

D.90-99

E. Cannot be determined.

Please explain your answer.

50-59-------------------------- 2

60-69--------------------------10

70-79--------------------------16

80-89--------------------------27

90-99--------------------------18

The table shown above has distribution of test scores. Which score interval contains the median of the 73 scores?

A.60-69

B.70-79

C.80-89

D.90-99

E. Cannot be determined.

Please explain your answer.

...

]]>

Bunuel wrote:

rpamecha wrote:

SCORE INTERVAL----------------NUMBER OF SCORES

50-59-------------------------- 2

60-69--------------------------10

70-79--------------------------16

80-89--------------------------27

90-99--------------------------18

The table shown above has distribution of test scores. Which score interval contains the median of the 73 scores?

A.60-69

B.70-79

C.80-89

D.90-99

E. Cannot be determined.

Please explain your answer.

50-59-------------------------- 2

60-69--------------------------10

70-79--------------------------16

80-89--------------------------27

90-99--------------------------18

The table shown above has distribution of test scores. Which score interval contains the median of the 73 scores?

A.60-69

B.70-79

C.80-89

D.90-99

E. Cannot be determined.

Please explain your answer.

...]]>

Car X and Car Y traveled the same 80-mile route. If Car X took 2 hours and Car Y traveled at an average speed that was 50 percent faster than the average speed of Car X, how many hours did it take Car Y to travel the route?

(A) 2/3

(B) 1

(C) 4/3

(D) 8/5

(E) 3

The speed of car X is (distance)/(time) = 80/2 = 40 miles per hour.

The speed of car Y = 3/2*40 = 60 miles per hour --> (time) = (distance)/(speed) = 80/60 = 4/3 hours.

Answer: C.

Or: to cover the same distance at 3/2 as fast rate

...

]]>

Car X and Car Y traveled the same 80-mile route. If Car X took 2 hours and Car Y traveled at an average speed that was 50 percent faster than the average speed of Car X, how many hours did it take Car Y to travel the route?

(A) 2/3

(B) 1

(C) 4/3

(D) 8/5

(E) 3

The speed of car X is (distance)/(time) = 80/2 = 40 miles per hour.

The speed of car Y = 3/2*40 = 60 miles per hour --> (time) = (distance)/(speed) = 80/60 = 4/3 hours.

Answer: C.

Or: to cover the same distance at 3/2 as fast rate

...]]>

If a, b, and c are three different positive integers whose sum is prime, which of the following statements could be true?

(A) Each of a, b, and c is prime.

(B) Each of a + 3, b + 3, and c + 3 is prime.

(C) Each of a + b, a + c, and b + c is prime.

(D) The average (arithmetic mean) of a, b, and c is prime.

(E) a + b = c

From Manhattan's Challenge for this week.

we know that all prime numbers are odd except 2. if 2 is also a part of these 3 positive numbers, then sum will always be even.

...

]]>

If a, b, and c are three different positive integers whose sum is prime, which of the following statements could be true?

(A) Each of a, b, and c is prime.

(B) Each of a + 3, b + 3, and c + 3 is prime.

(C) Each of a + b, a + c, and b + c is prime.

(D) The average (arithmetic mean) of a, b, and c is prime.

(E) a + b = c

From Manhattan's Challenge for this week.

we know that all prime numbers are odd except 2. if 2 is also a part of these 3 positive numbers, then sum will always be even.

...]]>

]]>

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.

]]>

Thanks to another GMAT Club member, I have just discovered this valuable topic, yet it had no discussion for over a year. I am now bumping it up - doing my job. I think you may find it valuable (esp those replies with Kudos).

Want to see all other topics I dig out? Follow me (click follow button on profile). You will receive a summary of all topics I bump in your profile area as well as via email.]]>

From question i understand that if 5 men worked together they would have completed 1 task n 100 day mean seach person will take 20 days to complete a task.

Than how come below

...

]]>

From question i understand that if 5 men worked together they would have completed 1 task n 100 day mean seach person will take 20 days to complete a task.

Than how come below

...]]>