BREAKING: Target Test Prep releases Brand New 2026 On Demand GMAT prep course

Redeem

21q17

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Master | Next Rank: 500 Posts
Posts: 496
Joined: Sun May 04, 2008 11:01 pm
Location: mumbai
Thanked: 7 times
GMAT Score:640

21q17

by stubbornp » Sat Oct 18, 2008 10:37 pm
17. What is the volume of a certain rectangular solid?
(1) Two adjacent faces of the solid have areas 15 and 24, respectively.
(2) Each of two opposite faces of the solid has area 40.
Top
Source: — Data Sufficiency |
Senior | Next Rank: 100 Posts
Posts: 41
Joined: Thu Jul 12, 2007 1:16 am
Location: Cape Town South Africa
Thanked: 5 times

by Saffa » Sun Oct 19, 2008 12:10 am
Both on their own is NOT SUFF as we don't have enough info:

Together:

Say Length = l, width = w and height = h

we're lloking for l x w x h = volume

but from (1): l x w = 15 and w x h = 24

from (2) l x h = 40

so now we have 3 unknowns with 3 equations, so you'll be able to work it out.

So IMO C.
Top
User avatar
Legendary Member
Posts: 543
Joined: Fri Jan 18, 2008 1:01 am
Thanked: 43 times
GMAT Score:580

by codesnooker » Sun Oct 19, 2008 1:22 am
(A) should be the answer.

L x W = 24 = 8 x 3
W x H = 15 = 5 x 3

So when you factorize above both equation, you can figure out the value of W = 3.

Therefore H = 5 and L = 8.

Hence volume = 3 x 5 x 8

Hence (A) is alone sufficient.
Top
Master | Next Rank: 500 Posts
Posts: 496
Joined: Sun May 04, 2008 11:01 pm
Location: mumbai
Thanked: 7 times
GMAT Score:640

by stubbornp » Sun Oct 19, 2008 7:25 am
codesnooker wrote:(A) should be the answer.

L x W = 24 = 8 x 3
W x H = 15 = 5 x 3

So when you factorize above both equation, you can figure out the value of W = 3.

Therefore H = 5 and L = 8.

Hence volume = 3 x 5 x 8

Hence (A) is alone sufficient.

Codesnooker,Isn't there is one case L x W=24 = 24 x 1
W x H=15 x 1

here we can figure out W=1...what do you say?
Top
User avatar
Legendary Member
Posts: 543
Joined: Fri Jan 18, 2008 1:01 am
Thanked: 43 times
GMAT Score:580

by codesnooker » Sun Oct 19, 2008 7:55 am
stubbornp wrote:
codesnooker wrote:(A) should be the answer.

L x W = 24 = 8 x 3
W x H = 15 = 5 x 3

So when you factorize above both equation, you can figure out the value of W = 3.

Therefore H = 5 and L = 8.

Hence volume = 3 x 5 x 8

Hence (A) is alone sufficient.

Codesnooker,Isn't there is one case L x W=24 = 24 x 1
W x H=15 x 1

here we can figure out W=1...what do you say?
Hmm. You are correct. My apologizes for the mistake.
Top
Junior | Next Rank: 30 Posts
Posts: 25
Joined: Wed Oct 29, 2008 7:26 pm

by gmattakers » Thu Oct 30, 2008 4:39 pm
I think both 1 and 2 are needed
Top
Post new topic Post Reply
• Page 1 of 1