BlueDragon2010 wrote:A rainstorm increased the amount of water stored in State J reservoirs from 124 billion gallons to 138 billion gallons. If the storm increased the amount of water in the reservoirs to 82 percent of total capacity, approximately 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
Do only as much math as necessary.
138 billion gallons is approximately 80% of the reservoir's capacity.
Implication:
The reservoir's capacity must be more than 150 billion gallons.
Test easy values greater than 150:
80% of 160 = 128.
80% of 170 = 136.
Success!
Thus:
The reservoir's capacity ≈ 170 billion gallons.
The amount of water lacking before the storm ≈ 170-124 ≈ 46.
The correct answer choice is
E.
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