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?
Let's be accurate as possible and think first.
170
The sell reduced the price of each pin by 20 *.

15 = $3.

So he paid 20 - 3 = $17 per pin.

So the total cost was 17 * 10 = $170.

.

The answer is 170