A rainstorm increased the amount of water stored in State J reservoirs from 130 billion gallons to 160 billion gallons. If the storm increased the amount of water in the reservoirs to 80 percent of total capacity, approximately how many billion gallons of water were the reservoirs short of total capacity prior to the storm?  Choose one.
A) 75	B) 70	C) 65	D) 85	E) 90
Let total capacity be x   we know 160 = 0.80x   x = 160/0.80= 
<gadget id="calculator">160/0.80</gadget>
<output>200</output>
200   Prior to storm, we had 130 bn gallons     200-130= 
<gadget id="calculator">  200-130</gadget>
<output>70</output>
70   Answer : 70
<result>B</result>
A rainstorm increased the amount of water stored in State J reservoirs from 130 billion gallons to 160 billion gallons. If the storm increased the amount of water in the reservoirs to 80 percent of total capacity, approximately how many billion gallons of water were the reservoirs short of total capacity prior to the storm?