You simply multiply the discount by the original price (remember to change the percent to a decimal). 0.30*31.50=9.45 So, the discount took $9.45 off of the original price.
As June21 explained, you can turn 30% into a decimal by dividing 100 into 30,(30/100), then multiply the $31.50 with 0.3 to get the amount after taken off the original price.
