Solving Problems About Percent Increase or Decrease

Mai started a new exercise program. On the second day, she walked 5 minutes more than on the first day. On the third day, she increased her walking time from day 2 by 20% and walked for 42 minutes. Mai drew a diagram to show her progress. Explain how the diagram represents the situation.

A store is having a sale where all shoes are discounted by 20%. Diego has a coupon for $3 off of the regular price for one pair of shoes. The store first applies the coupon and then takes 20% off of the reduced price. If Diego pays $18.40 for a pair of shoes, what was their original price before the sale and without the coupon?

A backpack normally costs $25 but it is on sale for $21. What percentage is the discount?

• 16%

• 17%

• 15%

• 14%

A stock increases in value by 5% from $100 to what value?

• $105

• $110

• $95

• $100.50

A car decreases in value by 15% over a year. If it was originally worth $20,000, what is its value after one year?

• $17,000

• $18,000

• $15,000

• $16,500

Does this question represent a percent INCREASE or a percent DECREASE?

• Increase

• Decrease

A population of 500 increases by 10% in a year. What is the new population?

• 550

• 600

• 510

• 500

A population of 5000 increases by 10% in a year. What is the new population?

• 5500

• 6000

• 500

• 4500

• 20%

• 25%

• 30%

• 15%