Question

Booker earned $1,200 over

the summer. He invested the money in
stocks. To his surprise, the stocks increased
in value to $1,335 in only 9 months. Find
the simple interest rate for the investment.

Answer 1

15%

Explanation:

1335-1200=135

9 months=9/12

135=1200 x r x 9/12

135=900r

divide each by 900

135/900 900r/900

0.15=r

0.15=15%