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

Redeem

Averages-DS question

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Junior | Next Rank: 30 Posts
Posts: 14
Joined: Tue Oct 21, 2008 10:37 pm

Averages-DS question

by kapitalist » Tue Apr 14, 2009 3:10 pm
In a certain group of people, the average (mean) weight of the males is 180 lbs and of the females, 120 lbs. What is the average weight of the people in the group.

1) The group contains twice as many females as males

2) The group contains 10 more females than males


answer A

I thought at first you cant compare to averages together? but the answer choice says something different? Please explain the problem so the next time I see it I can know that it can be solved and move on. Thanks.
Top
Source: — Data Sufficiency |
User avatar
MBA Student
Posts: 1194
Joined: Sat Aug 16, 2008 9:42 pm
Location: Paris, France
Thanked: 71 times
Followed by:17 members
GMAT Score:710

by gmat740 » Tue Apr 14, 2009 7:42 pm
Male Female
180 120
x 2x


avg = [x*180 + 2x*120] /x +2x

= 420x/3x
= 420/3
= 140

So, (I) is suff

II.

Male Female
180 120
x x+10

Avg = [x*180 + (x+10)*120]/x + x+10

= [30x + 1200]/2x+10

Unsolvable

So Insuff

Hence

Answer A

Hope this helps

Karan
Top
Junior | Next Rank: 30 Posts
Posts: 14
Joined: Tue Oct 21, 2008 10:37 pm

by kapitalist » Tue Apr 14, 2009 10:01 pm
thanks...

it was easier than I thought...I think i just had a brain fart. For some reason I have this notion that when AVG problems come up to be very skeptical on the choices because you are dealing with "averages."
Top
User avatar
MBA Student
Posts: 1194
Joined: Sat Aug 16, 2008 9:42 pm
Location: Paris, France
Thanked: 71 times
Followed by:17 members
GMAT Score:710

by gmat740 » Wed Apr 15, 2009 4:05 am
dont worry
Keep Practicing :D :D
Top
Post new topic Post Reply
• Page 1 of 1