human
John decided to buy 10 pins for himself. They are normally $20 each but they were on sale for 15% off. How much did he spend on pins?
assistant
How much did the sell reduce the price of each pin? ** The sell reduced the price of each pin by 20*.15=$<<20*.15=3>>3
How much did John pay for each pin? ** So he paid 20-3=$<<20-3=17>>17 per pin
How much did John spend on pins? ** So the total cost was 17*10=$<<17*10=170>>170
#### 170