geometry

This topic has expert replies
Master | Next Rank: 500 Posts
Posts: 138
Joined: Mon May 01, 2017 11:56 pm
Thanked: 4 times

geometry

by vaibhav101 » Fri Jun 08, 2018 11:34 pm

Timer

00:00

Your Answer

A

B

C

D

E

Global Stats

An umbrella 50 inches long can lie on the bottom of a trunk whose length and width in inches can be:

A 26 and 30
B 34 and 36
C 31 and 31
D 40 and 21
E 40 and 30
Source: — Problem Solving |

Legendary Member
Posts: 2898
Joined: Thu Sep 07, 2017 2:49 pm
Thanked: 6 times
Followed by:5 members

by Vincen » Mon Jun 11, 2018 12:48 am
Hello.

Here, we have to imagine the trunk as a rectangle, and we want to find its dimensions such that a 50 inches long umbrella can lie on it. If one of the sides of the rectangle (length or width) would be 50, then the umbrella would lie parallel to the respective side.

But, in the given options, all dimensions are lesser than 50. Therefore, we have to calculate the length of the diagonals of each given rectangle (the diagonal is the largest distance between two points of a rectangle).

The length of each diagonal is $$\left(A\right)\ D=\sqrt{26^2+30^2}\approx39.69\ $$ $$\left(B\right)\ D=\sqrt{34^2+36^2}\approx49.51$$ $$\left(C\right)\ D=\sqrt{31^2+31^2}\approx43.84$$ $$\left(D\right)\ D=\sqrt{40^2+21^2}\approx45.17$$ $$\left(E\right)\ D=\sqrt{40^2+30^2}=50.$$ As we can see, the umbrella can lie just in the last rectangle.

Therefore, the correct answer is the option E.

I hope it can help you.

User avatar
GMAT Instructor
Posts: 1462
Joined: Thu Apr 09, 2015 9:34 am
Location: New York, NY
Thanked: 39 times
Followed by:22 members

by Jeff@TargetTestPrep » Wed Jun 13, 2018 3:48 pm
vaibhav101 wrote:An umbrella 50 inches long can lie on the bottom of a trunk whose length and width in inches can be:

A 26 and 30
B 34 and 36
C 31 and 31
D 40 and 21
E 40 and 30
We need the diagonal of the trunk to be at least 50 inches. We know that the length, width and diagonal of the trunk obey the Pythagorean theorem, that is, L^2 + W^2 = D^2. Since D = 50, D^2 = 2500. So we need L^2 + W^2 ≥ 2500. Skimming through the answer choices, we see choice E will work since 40^2 + 30^2 is exactly 50^2.

Answer: E

Jeffrey Miller
Head of GMAT Instruction
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews