Math questions and topics from the Official Guide and Quantitative Review books. Please try to follow the posting pattern (e.g. OG - DS - #142) to allow for easier searches. Questions posted in the GMAT Math section regarding the OG have been moved here.
OnSunday
 
 

OG - PS - 73

by OnSunday Thu Sep 20, 2007 4:33 pm

I feel like I'm missing something here.

Equal amounts of water were poured into two empty jars of different capacities, which made one jar 1/4 full and the other jar 1/3 full. If the water in the jar with the lesser capacity is then poured into the jar with the greater capacity, what fraction of the larger jar will be filled with water?

a) 1/7
b) 2/7
c) 1/2
d) 7/12
e) 2/3

Shouldn't it be the jar that is 1/4 full (the smaller jar) be poured into the jar that is 1/3 full?
1/4 is 0.25, and 1/3 is 0.333... right?
Ali
 
 

by Ali Fri Sep 21, 2007 12:39 am

Equal amounts of water were poured into two empty jars of different capacities, which made one jar 1/4 full and the other jar 1/3 full. If the water in the jar with the lesser capacity is then poured into the jar with the greater capacity, what fraction of the larger jar will be filled with water?

a) 1/7
b) 2/7
c) 1/2
d) 7/12
e) 2/3


This is nothing more than a game of words.,

Understand this : Jar1 and Jar2 constitute different measurement, but what is equal is the amount poured so, Let's assume that 4 litres are poured in Jar 1 and 4 in Jar 2.

Jar1 is 1/4 full or it's total volume is x = 16 ( x * 1/4 = 4)
Now volume of Jar 2 is poured into Jar1, but here's what throws us off. We are not supposed to add the percentage but the volume of water poured in Jar2 i.e 4 litres to Jar 1 = so now Jar 1 has 8 litres

8/16 = 1/2 - Answer is C.

Thanks
StaceyKoprince
ManhattanGMAT Staff
 
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by StaceyKoprince Mon Sep 24, 2007 10:18 pm

Yep - the one that is 1/4 full is NOT the smaller jar. It's the larger jar because the same amount of water fills a smaller fraction of the jar. Try it at home to visualize!
Stacey Koprince
Instructor
Director, Content & Curriculum
ManhattanPrep