Give the step-by-step reasoning process and then the final answer. John plays at the arcade for 3 hours. He uses $.50 for every 6 minutes. How much money did he spend, in dollars?
He was at the arcade for 3 * 60 = 180 minutes. So he put coins in 180 / 6 = 30 times. That means he spent 30 * .5 = $15.
The final answer: 15.