If Henry were to add 9 gallons of water to a tank that is already 3/4 full of water, the tank would be 7/8 full. How many gallons of water would the tank hold if it were full? Answers.
A) 25  B) 40  C) 64  D) 72  E) 96

Rationale: "7 / 8 x - 3 / 4 x = 9 galls 1 / 8 * x = 9 gallons x = 72 gallons answer d"
Answer: D