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?

16 2/3 % 1.) = = ) ) = – 1125 = ) 0.64 – %

More Applications of Percents Lesson 8.7

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!)

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 = I = $3,240 Not your answer! Total pay = ,240 Total pay = $16,740

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 = t 525 = 150t years = t

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 = I = $150 Not your answer! Total = $2150 Total =

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

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 = I = $ Not your answer! Total = Total = $13,687.50

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 = r = r Never told us amount of interest, but we can find it! (amount to repay) (amount borrowed) (our interest!) 6.5% = r