1. Warm-up What is 35 increased by 8%? What is the percent of decrease from 144 to 120? What is 1500 decreased by 75%? What is the percent of increase from 0.32 to 0.64?

2. 16 2/3 % 1.) 35.08 = 2.8 35 + 2.8 = 37.8 2.) 144 - 120 144 24 144 3.) 1500.75 = 1125 1500 – 1125 = 375 4.) 0.64 – 0.32 0.32 100%

3. More Applications of Percents Lesson 8.7

4. I = P r t I = Interest P = Principal (or starting amount of money r = rate (must be in decimal form!) t = time (time in years!)

5. Thurman borrowed $13,500 from his brother-in- law for 4 years at an annual simple interest rate of 6% to buy a car. How much interest will he pay if he pays the entire loan off at the end of the fourth year? What is the total amount he will repay? I = P r t I = 13500.06 4 I = $3,240 Not your answer! Total pay = 13500 + 3,240 Total pay = $16,740

6. Tony invested $3000 in a mutual fund at a yearly rate of 5%. He earned $525 in interest. How long was the money invested? I = P r t 525 = 3000.05 t 525 = 150t 150 3.5 years = t

7. Rebecca’s grandmother deposited $2000 into a savings account as a college fund. How much will Rebecca have in this account after 3 years at a yearly simple interest rate of 2.5%? I = P r t I = 2000.025 3 I = $150 Not your answer! Total = $2150 Total = 2000 + 150

8. Suzanne borrowed $5000 for 5 years at simple interest to pay for her college classes. If Suzanne repaid a total of $6187.50, at what interest rate did she borrow the money? I = P r t 1187.50 = 5000 r 5 1187.50 = 25000r 25000.0475 Never told us amount of interest, but we can find it! 6187.50 (amount to repay) - 5000.00 (amount borrowed) 1,187.50 (our interest!) 4.75% = r

9. Anne deposits $7500 in a college fund for her niece. If the fund earns an annual simple interest rate of 5.5%, how much will be in the fund after 15 years? I = P r t I = 7500.055 15 I = $6187.50 Not your answer! Total = 7500 + 6187.50 Total = $13,687.50

10. First Bank loaned a construction company $125,000 at an annual simple interest rate. After 3 years, the company repaid the bank $149,375. What was the loan’s interest rate? I = P r t 24375 = 125000 r 3 24375 = 375000r 375000.065 Never told us amount of interest, but we can find it! 149375 (amount to repay) - 125000 (amount borrowed) 24375 (our interest!) 6.5% = r