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

Redeem

simple math from OG11

This topic has expert replies
Post new topic Post Reply
Previous Topic Next Topic
Newbie | Next Rank: 10 Posts
Posts: 3
Joined: Mon Jan 12, 2009 9:24 am

simple math from OG11

by Maggie12 » Tue Jan 20, 2009 9:26 pm
Hi

can anyone solve the problem

A rainstorm increased the amount of water stored in State J reservoirs from 124 billion gallons to 138 billion gallons. If the storm increase the amount of water in the reservoirs to 82 percent of total capacity, approx how many billion gallons of water were the reservoirs short of total capacity prior to the storm?

A 9

B 14

C 25

D 30

E 44
Top
Source: — Problem Solving |
Master | Next Rank: 500 Posts
Posts: 160
Joined: Sat Dec 20, 2008 9:12 pm
Thanked: 11 times

by aroon7 » Tue Jan 20, 2009 9:52 pm
OA is E

138 = (82/100)(Total capacity)
Ans is Total capacity - 124

this will be approx. 44

This is an OG-11 problem: Page 152, Q# 6

please let me know if you still have problems
--------------------------
i am back!
Top
Junior | Next Rank: 30 Posts
Posts: 26
Joined: Mon Oct 27, 2008 1:01 pm
Thanked: 1 times

by 480ocean » Wed Jan 21, 2009 5:29 pm
As illustrated in the previous post, the formula you can use is: Part = % * Whole

138 = 82% * Whole
(Whole means the total amount of water at 100% full - which means total capacity, which is unknown)
138 = .82 * Whole
Divide both sides by .82
168 = Whole

Then,
168 - 124 = 44 billion gallons short of total capacity prior to the storm.

Hope this helps too!
Top
Post new topic Post Reply
• Page 1 of 1