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Home > MC2 > Chapter 9 > Lesson 9.2.3 > Problem 9-66

  1. Calculate the percent change in each problem below. Homework Help ✎

    1. Robert wanted to buy a computer game that cost $25 last week. This week when he went back to buy the game, the price was $35. What was the percent of increase in the price?

    2. Susan bought a jacket on sale. The original price of $35 was marked down to $25. What was the percent discount because of the sale?

    3. Why were your answers to parts (a) and (b) different?

Find the increase in the price and find it as a percentage of the original price.

Increase: $35 − $25 = $10

$10 = (x)($25)

Follow the same strategy to find the percent discount. Remember, the percent discount is with respect to the original price.


The percent increase is the amount the price increased as a percentage of the original cost.

Each percentage is based on different original prices.