Igot 40% off when i purchased a set of golf balls regularly priced at $19.50. how much did i pay?

Your answer is:

40%=40/100=.4

$19.50 *.4=$7.80 discount

$19.50-$7.80=$11.70 paid

First, you would find 40% of 19.50 to find how much is off. To do this, you would do 0.40 x 19.50, which is 7.8. Then, you would subtract 19.50 and 7.8, which is 11.7. Therefore, you paid $11.7