After a storm deposits 110 billion gallons of water into the city reservoir, the reservoir is 60% full. If the original contents of the reservoir totaled 220 billion gallons, the reservoir was approximately what percentage full before the storm?  Choose the correct option.
A) 40 %
B) 48 %
C) 54 %
D) 58 %
E) 65 %

Rationale: when the storm deposited 110 billion gallons , volume of water in the reservoir = 220 + 110 = 360 billion gallons if this is only 60 % of the capacity of the reservoir , the total capacity of the reservoir = 330 / 0.6 = 550 billion gallons therefore percentage of reservoir that was full before the storm = ( 220 / 550 ) * 100 = 40 % option a
Answer: A