Question

Sam opened a money-market account that pays 2% simple interest. He started the account with $7,000 and made no further deposits. When he closed the account, he had earned $280 in interest. How long did he keep his account open?

A. 2 years
B. 5 years
C. 3 years
D. 4 years

Answer 1

2 years. He kept his account open for 2 years.

Answer 2

The formula for simple interest =

I = PRT
P = initial capital = $7000
R = rate = 0.02 in this case
T = time = our variable we are solving for

Thus substitute the parts into the equation we get
280 = 7000*0.02*T
Solving for T we get A or 2 years