John plays at the arcade for 3 hours.  He uses $.50 for every 6 minutes.  How much money did he spend, in dollars?
How many minutes did John spend at the arcade? ** He was at the arcade for 3*60=<<3*60=180>>180 minutes
How many times did John put coins in? ** So he put coins in 180/6=<<180/6=30>>30 times
How much money did John spend? ** That means he spent 30*.5=$<<30*.5=15>>15
#### 15