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?
3 Explanations
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Elias Toulany
Hi,
What I did is round 138 to 140 and 82% to 80%.
Then I found 10% of 140, being 14.
Then I multipliked 14 by 2 to find 20% - being 28.
I took 28 (20%) and added to 140 (~80%) for 168 (100%).
Is this correct?
My numbers are definitly different than yours - but I still got the correct answer 44 at the end.
The odd thing with your route is that 10% of 140 ends up being 17.5 - but my route has 10% of 140 being 14!
If we don't approximate initially we get approx 34 so why can't be select the answer D. My question is when do when to approximate first before actually doing the calculations with the values given?
3 Explanations