Problem: a rainstorm increased the amount of water stored in state j reservoirs from 50 billion gallons to 75 billion gallons . if the storm increased the amount of water in the reservoirs to 37.5 percent of total capacity , approximately how many billion gallons of water were the reservoirs short of total capacity prior to the storm ?
Rationale: after the reservoir is filled to 75 gallons the amount of water is at 37.5 % - which means that 62.5 % of the reservoir is empty . to figure out what that 62.5 % is approximate : 75 gallons / 37.5 percent = x gallons / 62.5 percent , therefore , x = 125 gallons , answer choices a , b , c , d are below 125 . we know that the reservoir must be short more than 125 gallons , therefore , the only possible choice is e .
annotated_formula: divide(divide(multiply(75, const_100), 37.5), const_2)