After 4 years, Aspen earned $510 in simple interest from a CD into witch she initially deposited $3000. What was the annual interest rate of the CD?

Interest = 510

Principal = 3000

Rate = x

Time = 4

 

510 = (3000) (x) (4)

3000x 4 = 12000

 

510 = 12000

12000/510 = 23.5

$510 /4 =$127.50 simple interest earned per year.

$127.50 / $3,000 =0.0425 x 100 =4.25% simple annual interest earned on the $3,000 investment.