Practice Questions Chat

[quote="gmatophobia"] DS Question 1 - Mar 05 At a certain animal shelter, there are nine dogs available for adoption. If Susan chooses two dogs at random and p is the probability that Susan chooses two labradors, is p =3 makes condition on "p" true, hence we have check if number of Labradors =3 ?


STATEMENT 1:

we can form equation :
(x/9 * y/8) + (y/9 * x/8) > 1/2

2xy > 1/2 * 72
x(9-x) > 18

we can test some values of x starting from 9 to 0 descending we find only x=5 or x=4 satisfy the above condition. so x 1/10
y(y-1) > 7.2

trying you values of y, we get y=4 onwards all values satisfy the condition above. so y>=3 holds true as asked in question stem. so statement is also sufficient.


BOTH statement is sufficient ?
option D

DS Question 1 - Mar 07

If a = |b - 6| + |b + 2|, what is the value of a ?

(1) a is an integer greater than 7
(2) -2 < b < 6

Source: GMATNinja | Difficulty: Hard

PS Question 1 - Mar 07

If Z = 10^x + 10^y + 10^z , in which x, y, z are distinct positive integers. How many different values of Z are possible if Z < 10^9?

a) 24
b) 34
c) 56
d) 84
e) 120

Source: Others | Difficulty: Hard

From observation , we see if either of x,y,or z has be less than 9 , else z would be greater than 10^9. so max value of either of x,y,or z is 8. And since it is also given x,y,z are distinct +ve int. then we have max value x,y,z can be 8*7*6/3! ( as 10^1+10^2+10^3 is same as 10^3+10^2+10^1). Answer is C

B ??

B, since every value of a when -2 < b < 6 is 8.

Can we create something similar for whatsap? Many people dont longin daily to this chat, just a good for thought.

This can be rewritten as p^(m*n)=256.

16^2 = 256
4^4 = 256
2^8 = 256

16^2=4^2=2^8

Thus, m*n can be 2, 4, or 8.

Then possible values of n = 1, 2, 4, 8

So, possible values of n*n = 1, 4, 16, 64

B. I & III

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We don’t encourage use of 3rd party messengers. The reason we have this chat group is to collaborate and learn.

PS Question 1 - Mar 09

Fox jeans regularly sell for $15 a pair and Pony jeans regularly sell for $18 a pair. During a sale these regular unit prices are discounted at different rates so that a total of $9 is saved by purchasing 5 pairs of jeans: 3 pairs of Fox jeans and 2 pairs of Pony jeans. If the sum of the two discounts rates is 22 percent, what is the discount rate on Pony jeans?

A. 9%
B. 10%
C. 11%
D. 12%
E. 15%

Source: GMAT Paper Tests | Difficulty: Hard

DS Question 1 - Mar 09

Joe earned x dollars the first day he worked in December, where x is an integer. For each day after the first that he worked in December, Joe earned twice the amount he earned on the previous day. Did Joe earn less than $35 on the 4th day he worked in December?

(1) Joe earned more than $120 in total for the first five days he worked in December.
(2) Joe earned less than $148 on the 6th day he worked in December.

Source: Manhattan Prep | Difficulty: Hard

System of equations: let x be discount on Fox jeans and y discount on Pony jeans.

B.

A.

PS Question 1 - Mar 10

If (a + b) = 4, and ab = 7/4, what is the value of a^2 – b^2?

A. -12
B. 12
C. Either A or B
D. 16
E. None

Source: Official Guide | Difficulty: Medium

DS Question 1 - Mar 10

Is x > y^2?

(1) x > y + 5

(2) x^2 - y^2 = 0

Source: GMAT Club Tests | Difficulty: Hard

a^2-b^2 = (a+b)(a-b) , we already know a+b , so for (a-b)^2 can be written as (a+b)^2-4ab , hence a-b = 3 or -3, hence a^2-b^2 = 4*3 i.e 12 or 4*-3 =-12

PS Question 1 - Mar 11

The ratio of a two digit number to a number formed by reversing its digits is 4:7. Which of the following is the sum of all the numbers of all such pairs?

A. 110
B. 200
C. 330
D. 88
E. 770

Source: Others | Difficulty: Medium

DS Question 1 - Mar 11

W, X, Y and Z are four different positive integers. When X is divided by Y, the quotient is Z and the remainder is W.
What is the value of Z?

1) W = X – 4
2) W + Z = 4

Source: GMATPrepNow | Difficulty: Hard

(10a+b) / (10b+a) = 4:7
=> 2a=b
or b is even, for a number "ab" and "a" is half of "b"
such numbers are = 12,24,36,48
and "ba" to form pair = 21,42,63,84

sum of above all number pairs = 330 option C

X=YZ+W
find Z
statement1:
W=X-4
so, YZ=4 since X,Y,Z,W are different positive int;
Y=4 OR 1, Y is used to divide the number X, if its 1 there will be no remainder
but W is a positive number, so Y IS NOT hence Y = 4 and Z=1
so sufficient

statement2:
YZ-Z+4=X
still too many variables to account for. not conclusive
(W,Z) = (1,3) , (2,2) SO ON

Option A ?

C , (10a+b)/(10b+a)=4/7 , we get a=2b , now putting values in b such that 10a+b and 10b+a remains 2 digit numbers , we get 21,42,63,84 (10a+b) and 12,24,36,48 (10b+a) , adding them all we get 330.

A??

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1) YZ = 4 so it can be (2,2) or (1,4) or (4,1) so 1 is not sufficient
2) W + Z = 4, so it can be (3,1), (1,3) or (2,2) so 2 is not sufficient
1) + 2) combined the common values are 2,2 so C