Simple and Compound Interest

Find the simple interest.

principal= $870
interest rate= 6%
time= 9 months

Please help me I need the answer for tommorow.

3 answers

simple interest = principal x rate x time
= 870(.06)(9/12) = .....
The simple interest paid on a loan after 6 months was $306. The annual interest rate was 8%. Find the principal
I = P*r*t = 306.
P*(0.08/12)*6 = 306,
P = $7,650.