It is currently 21 Nov 2017, 21:12

Close

GMAT Club Daily Prep

Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized
for You

we will pick new questions that match your level based on your Timer History

Track
Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice
Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Close

Request Expert Reply

Confirm Cancel

Events & Promotions

Events & Promotions in June
Open Detailed Calendar

Math Revolution Approach (PS)

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  
Author Message
Intern
Intern
avatar
B
Joined: 15 Oct 2014
Posts: 18

Kudos [?]: 2 [0], given: 150

Reviews Badge
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 09 Feb 2017, 05:41
MathRevolution wrote:
If (n+2)!/n!=156, n=?
A. 2/131 B. 9 C. 10 D. 11 E. 12

==> From (n+2)!/n!=156 and (n+2)(n+1)n!/n!=(n+2)(n+1)=156=13*12, you get n+2=13, n=11.

Therefore, the answer is D

Adding to this since it's a quadratic we will get 2 solutions 11,-14 but since -14 is not an option so n=11 is correct.


Sent from my iPhone using GMAT Club Forum mobile app

Kudos [?]: 2 [0], given: 150

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 12 Feb 2017, 18:25
What is the difference between the circumferences of 2 circles such that the diameters of the circles are 10 and 11?

A. \(\frac{π}{2}\)
B. \(π\)
C. \(3\frac{π}{2}\)
D. \(2π\)
E. \(5\frac{π}{2}\)

==> The circumference of a circle is \(π\)d, thus \(π(11-10)= π\).

Therefore, the answer is B.
Answer: B
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 12 Feb 2017, 18:27
What is the number of multiples of 25 between \(5^4\) and\(5^5\), inclusive?

A. 75
B. 96
C. 101
D. 121
E. 125

==> The number of multiples become (last-first/n)+1, then you get \(\frac{5^5-5^4}{25}+1=\frac{(5-1)5^4}{25}+1=4(5^2)+1=101\).

Therefore, the answer is C.
Answer: C
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 15 Feb 2017, 01:08
If 1 male, 2 females, and 1 child are to be randomly selected from 8 males, 10 females, and 8 children, how many such cases are possible?

A. 980
B. 1,440
C. 1,880
D. 2,480
E. 2,880

==> You get 8C1*10C2*8C1=(8)(45)(8)=2,880.

The answer is E.
Answer: E
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 18 Feb 2017, 08:04
What is the range of 30 consecutive even numbers?

A. 54
B. 56
C. 58
D. 60
E. 62

==> The number of consecutive numbers become (last-first/2)+1=(range/2)+1. In other words, from (range/2)+1=30, you get range/2=29, range=2(29)=58.

The answer is C.
Answer: C
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 18 Feb 2017, 08:08
\(8^1^0-8^2\) is the approximation of which of the following?

A. \(8^7\)
B. \(8^8\)
C. \(8^9\)
D. \(8^1^0\)
E. \(8^1^1\)

==> You get \(8^1^0-8^2=(8^8-1)8^2≒(8^8)(8^2)=8^1^0\).

The answer is D.
Answer: D
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 19 Feb 2017, 18:45
When \(f(x)=x^2(1-x)^2\), which of the following is equal to f(1-x)?

A. f(x)
B. f(x)/x
C. f(-x2)
D. f(x2)
E. f(1)

==> You get \(f(1-x)=(1-x)^2(1-(1-x))^2=(1-x)^2x^2=f(x)\).

Therefore, the answer is A.
Answer: A
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 19 Feb 2017, 18:47
Which of the following equivalent to \((1/8)^4\)?

A. \((0.5)^5\)
B. \((0.25)^3\)
C. \((0.25)^6\)
D. \((0.4)^3\)
E. \((0.8)^2\)

==> You get \((1/8)^4=((1/2)^3)^4=(1/2)^1^2=((1/2)^2)^6=(1/4)^6=(0.25)^6\).

Therefore, the answer is C.
Answer: C
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 23 Feb 2017, 01:10
What is the difference between the hypotenuse’s length of the right triangle with 2 shorter sides of 10 and 24 and the hypotenuse’s length of the right triangle with 2 shorter sides of 7 and 24?

A. 1
B. 2
C. 3
D. 4
E. 5

==>For Pythagorean Theorem, 5:12:13=10:24:26 and 7:24:25 appear most frequently. Thus, the length of hypotenuse each becomes 26 and 25, and the difference becomes 26-25=1.

The answer is A.
Answer: A
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 24 Feb 2017, 02:14
10+8÷3×6-2=?

A. 24
B. 34
C. 22
D. 12
E. 11

==> When calculating the numbers, even if there are no brackets, multiplication and division come first.
You get 10+8÷3×6-2=10+(8/3)6-2=10+16-2=24.

The answer is A.
Answer: A
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Manager
Manager
avatar
B
Joined: 21 Feb 2017
Posts: 86

Kudos [?]: 3 [0], given: 23

GMAT ToolKit User
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 25 Feb 2017, 23:20
MathRevolution wrote:
In the x- y plane, there are 4 points (0,0), (0,4), (6,4), and (6,0). If these 4 points makes a rectangle, what is the probability that x+y<4?
A. 1/2
B. 1/3
C. 1/4
D. 1/5
E. 2/5

ANS: As you can see from the diagram below, the correct answer is 1/3. Hence, B is our answer choice.

Please describe how 1/3 is correct?

Kudos [?]: 3 [0], given: 23

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 26 Feb 2017, 21:30
Attachment:
1.png
1.png [ 2.59 KiB | Viewed 229 times ]

There is a circle inscribed in a square, shown on the above figure. If the length of the square is 2, what is the area of one of the 4 regions shaded?

A. \(1-π\)
B. \(2-π\)
C. \(4-π\)
D. \(1-(\frac{π}{2})\)
E. \(1-(\frac{π}{4})\)

==> The area of the square-area of the \(circle=2^2- π=4- π\), and since it asks for one of the 4 regions shaded, you get \(\frac{4- π}{4}=1-(\frac{π}{4})\).

The answer is E.
Answer: E
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 26 Feb 2017, 21:34
Expert's post
1
This post was
BOOKMARKED
What is the scope including 1/11+1/12+1/13+......+1/20?

A 1/6~1/5
B. 1/5~1/4
C. 1/4~1/3
D. 1/3~1/2
E. 1/2~1

==>The sum of consecutive reciprocal number sequence is decided by the first number and the last number. Thus, from
10/20=1/11+1/12+.....+1/20<1/11+1/12+.....+1/20<1/11+1/12+.....+1/20=10/11, you get 1/2=10/20<1/11+1/12+.....+1/20<10/11<1, which becomes 1/2~1.

Therefore, the answer is E.
Answer: E
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Math Revolution Approach (PS) [#permalink]

Show Tags

New post 26 Feb 2017, 21:50
MathRevolution wrote:
In the x- y plane, there are 4 points (0,0), (0,4), (6,4), and (6,0). If these 4 points makes a rectangle, what is the probability that x+y<4?
A. 1/2
B. 1/3
C. 1/4
D. 1/5
E. 2/5

ANS: As you can see from the diagram below, the correct answer is 1/3. Hence, B is our answer choice.

Attachments

1.png
1.png [ 10.85 KiB | Viewed 209 times ]


_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo


Last edited by MathRevolution on 26 Feb 2017, 22:23, edited 2 times in total.

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Math Revolution Approach (PS) [#permalink]

Show Tags

New post 26 Feb 2017, 21:55
As you can see from the diagram above, the area of the red rectangle is 24 and the area of the triangle below green line is 8.
The ratio of the area of the triangle to that of the red rectangle is 1/3.
Hence, B is our answer choice.
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Math Revolution Approach (PS) [#permalink]

Show Tags

New post 26 Feb 2017, 22:14
awdxzs wrote:
MathRevolution wrote:
If (n+2)!/n!=156, n=?
A. 2/131 B. 9 C. 10 D. 11 E. 12

==> From (n+2)!/n!=156 and (n+2)(n+1)n!/n!=(n+2)(n+1)=156=13*12, you get n+2=13, n=11.

Therefore, the answer is D

Adding to this since it's a quadratic we will get 2 solutions 11,-14 but since -14 is not an option so n=11 is correct.


Sent from my iPhone using GMAT Club Forum mobile app


Hello, goalMBA1990

The area of the red rectangle is 24 and the area of the triangle below green line is 8. The ratio of the area of the triangle to that of the red rectangle is 1/3.
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 26 Feb 2017, 22:22
As you can see from the diagram above, the area of the red rectangle is 24 and the area of the triangle below the green line is 8.
The ratio of the triangle area to the red rectangle area is 8/24 or 1/3.
Hence, B is our answer choice.
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 26 Feb 2017, 22:25
As you can see from the diagram below, the area of the red rectangle is 24 and the area of the triangle below green line is 8.
The ratio of the area of the triangle to that of the red rectangle is 1/3.
Hence, B is our answer choice.
Attachments

1.png
1.png [ 10.85 KiB | Viewed 209 times ]


_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 01 Mar 2017, 04:50
40,105*26*10,112 is the approximation of which of the following?

A. \(10^8\)
B. \(10^9\)
C. \(10^1^0\)
D. \(10^1^1\)
E. \(10^1^2\)

==> You get \(40,105*26*10,112≒40,000*25*10,000=100*10^4*10^4=10^2*10^4*10^4=10^2^+^4^+^4=10^1^0\).

The answer is C.
Answer: C
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Expert Post
Math Revolution GMAT Instructor
User avatar
P
Joined: 16 Aug 2015
Posts: 4341

Kudos [?]: 3048 [0], given: 0

GPA: 3.82
Premium Member CAT Tests
Re: Math Revolution Approach (PS) [#permalink]

Show Tags

New post 02 Mar 2017, 01:39
The standard deviation of which of the following is equivalent with that of \({m, r, p, n}\)?

A. {\({2m, 2r, 2p, 2n}\)}
B. {\({m+2, r+2, p+2, n+2}\)}
C. {\({|m|, |r|, |p|, |n|}\)}
D. {\({\frac{1}{m}, \frac{1}{r}, \frac{1}{p}, \frac{1}{n}}\)}
E. {\({m^2, r^2, p^2, n^2}\)}

==> For standard deviation, if the elements move in parallel, they have the same standard deviation. Thus, the standard deviation of {m, r, p, n} is equal to the standard deviation of {m+2, r+2, p+2, n+2}.

Therefore, the answer is B.
Answer: B
_________________

MathRevolution: Finish GMAT Quant Section with 10 minutes to spare
The one-and-only World’s First Variable Approach for DS and IVY Approach for PS with ease, speed and accuracy.
Find a 10% off coupon code for GMAT Club members.
“Receive 5 Math Questions & Solutions Daily”
Unlimited Access to over 120 free video lessons - try it yourself
See our Youtube demo

Kudos [?]: 3048 [0], given: 0

Re: Math Revolution Approach (PS)   [#permalink] 02 Mar 2017, 01:39

Go to page   Previous    1  ...  5   6   7   8   9   10   11  ...  18    Next  [ 341 posts ] 

Display posts from previous: Sort by

Math Revolution Approach (PS)

  new topic post reply Question banks Downloads My Bookmarks Reviews Important topics  


GMAT Club MBA Forum Home| About| Terms and Conditions| GMAT Club Rules| Contact| Sitemap

Powered by phpBB © phpBB Group | Emoji artwork provided by EmojiOne

Kindly note that the GMAT® test is a registered trademark of the Graduate Management Admission Council®, and this site has neither been reviewed nor endorsed by GMAC®.