Here are the answers to practice problem No. 6.1. If you are evaluating a pump tank and pump system and you measure the dimensions to be 49 inches wide by 68 inches long by 62 inches deep, calculate the gallons per inch.Answer: There are a couple of ways to calculate the gallons per inch, but the easiest way is to take the length times width in feet, times 1 foot of tank depth to get the gallons and divide by 12 inches to get the answer in gallons per inch.So to convert 68 inches and 49 inches to feet;68 in ÷ 12
