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.

It appears that you are browsing the GMAT Club forum unregistered!

Signing up is free, quick, and confidential.
Join other 500,000 members and get the full benefits of GMAT Club

Registration gives you:

Tests

Take 11 tests and quizzes from GMAT Club and leading GMAT prep companies such as Manhattan GMAT,
Knewton, and others. All are free for GMAT Club members.

Applicant Stats

View detailed applicant stats such as GPA, GMAT score, work experience, location, application
status, and more

Books/Downloads

Download thousands of study notes,
question collections, GMAT Club’s
Grammar and Math books.
All are free!

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

Re: In the rectangular solid above, the three sides shown have [#permalink]

Show Tags

02 Jun 2013, 06:41

1

This post received KUDOS

What if the actual test the same questions with very big number? will the same technique hold good? that may take some massive time with bigger numbers.

What if the actual test the same questions with very big number? will the same technique hold good? that may take some massive time with bigger numbers.

Real GMAT questions, including 700+ questions, do not require tedious math, so even with some big numbers there would be some shortcut possible
_________________

In the rectangular solid above, the three sides shown have areas 12, 15, and 20, respectively. What is the volume of the solid?

(A) 60 (B) 120 (C) 450 (D) 1,800 (E) 3,600

Say the dimensions of the rectangular solid are x by y by z, then the volume is xyz.

We are given that:

xy=12; xz=15; yz=20.

Multiply all three: (xyz)^2=12*15*20=3,600 --> xyz=volume=60.

Answer: A.

What's the rationale behind multiplying all 3?

We need to find the volume, which is xyz. When we multiply we get (xyz)^2, so to get the volume all we need to do is to take the square root from it .
_________________

Re: In the rectangular solid above, the three sides shown have [#permalink]

Show Tags

21 Sep 2015, 09:29

Hello from the GMAT Club BumpBot!

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.
_________________

Re: In the rectangular solid above, the three sides shown have [#permalink]

Show Tags

01 Feb 2016, 02:47

Walkabout wrote:

Attachment:

volume.png

In the rectangular solid above, the three sides shown have areas 12, 15, and 20, respectively. What is the volume of the solid?

(A) 60 (B) 120 (C) 450 (D) 1,800 (E) 3,600

We could see that the horizontal rectangular is the largest area, so it is 20. The second largest is 15, and the vertical rectangular on the right is 12. All of the rectangles share side. And the formula for area is l * w. For the smallest rectangular: 12 = 3 * 4, and 15 = 5 * 3, where they share side 3 with each other. 20 = 4 * 5. And the volume for a box is l * h * w = 3 * 4 * 5 = 60

Re: In the rectangular solid above, the three sides shown have [#permalink]

Show Tags

01 Jun 2016, 06:38

Walkabout wrote:

Attachment:

volume.png

In the rectangular solid above, the three sides shown have areas 12, 15, and 20, respectively. What is the volume of the solid?

(A) 60 (B) 120 (C) 450 (D) 1,800 (E) 3,600

We are given a rectangular solid and also are given areas of three of the sides. Let’s draw the figure out. We label the length, width, and height. We also label each side as side A, side B, and side C.

We see that the area of side A is length times height, that of side B is length times width, and that of side C is height times width.

We are given that the sides have areas of 12, 15, and 20.

Let’s say:

Side A area = 20

Thus we can set up the following equation for area:

length x height = 20

Side B area = 15

Thus we can set up the following equation for area:

length x width = 15

Side C area = 12

height x width = 12

Analyzing the two equations, length x height = 20 and length x width = 15, we see that both 15 and 20 are multiples of 5 and we also see that each equation contains the common term of “length”. Thus, we can deduce that the length could equal 5. When length is 5, we see height is 4, and when length is 5, we see that width is 3. We now have our dimensions for length, width, and height.

length = 5

width = 4

height = 3

Since volume of a rectangular solid = length x width x height, the volume is:

5 x 4 x 3 = 60.

The answer is A.

(Note: If we were struggling to know which side, was side A, B, and C, we could have selected those sides in any order and we would have ended up with the same value for the volume. If that were not the case, we would have to have been given more specific instructions about which sides corresponded to which areas.)
_________________

Jeffrey Miller Scott Woodbury-Stewart Founder and CEO

gmatclubot

Re: In the rectangular solid above, the three sides shown have
[#permalink]
01 Jun 2016, 06:38

Happy New Year everyone! Before I get started on this post, and well, restarted on this blog in general, I wanted to mention something. For the past several months...

It’s quickly approaching two years since I last wrote anything on this blog. A lot has happened since then. When I last posted, I had just gotten back from...

Post-MBA I became very intrigued by how senior leaders navigated their career progression. It was also at this time that I realized I learned nothing about this during my...