human
John buys 20 candy bars. His brother Dave pays for 6 of them. If each candy bar costs $1.50, how much did John pay?
assistant
How many candy bars did John pay for? ** He paid for 20-6=<<20-6=14>>14 candy bars
How much did John pay? ** So he paid 14*1.5=$<<14*1.5=21>>21
#### 21