Question: A pickup truck can fill 20 eight gallon water cans (each can filled three quarters of its capacity) in three hours. If each can is filled to full capacity instead, how long, in hours, will it take to fill 25 cans? Think carefully first, then make a decision:
Each can is filled with 8 / 4 * 3 = 6 gallons of water. A total of 6 * 20 = 120 gallons of water is filled in 3 hours. In 1 hour, 120 / 3 = 40 gallons of water is filled. 25 full cans can hold 25 * 8 = 200 gallons of water. It will take 200 / 40 = 5 hours to fill 25 cans to full capacity. So the answer is 5.