Some percent problems involve finding a percent of increase or decrease. Two examples are shown below.

The sales tax on a purchase is a percent of the purchase price. To find the total price, you must calculate the amount of sales tax and add it to the purchase price.

Let's Practice: Find the final price of each item. When there is a discount and sales tax, compute the discount price first.

1. Compact Disk: $16.00 before a 14% discount

$13.60

3. Airline Ticket: $248.00 before a 33% Superair discount

$166.16

5. Class ring: $89 before a 17% Group discount but requires a 5% Sales tax

$77.56

2. Two concert tickets: $28.00 before a 28% student discount

$20.16

4. Celebrity Photo Calendar: $10.95 before a 7.5% Sales tax

$11.77

6. Computer Software: $44.00 before a 21% discount but requires a 6% Sales tax

$36.85

Solve each problem

7. The original selling price of a new sports video was $65.00. Due to demand, the price was increased to $87.75. What was the percent of increase over the original price?

35%

8. A high school paper increased it sales by 75% when it ran an isue featuring a contest to win a class party. Before the contest issue, 10% of the school's 800 students bought the paper. How many students bought the contest issue?

140