Find the answer to this math problem: Tony has a bucket that holds 2 pounds of sand. He has a sandbox out back that is two feet deep, four feet wide, and 5 feet long. A cubic foot of sand weighs 3 pounds. Because it's hot outside, he wants to make sure he stays hydrated, so every 4 trips he takes he drinks 3 ounces of bottled water. A 15 ounce bottle of water costs $2. He has $10 with him. How much change will he have after he buys all the water he needs?