Answer:
See below.
Explanation:
I = PRT/100 will do it.
I = Simple interest.
P = Principal ( Intial Amount invested).
R = Rate (as a percent).
T = time invested.
The above formula gives the amount of interest, If you want to find the interest rate knowing all the other values you have to solve for R:
I = PRT/100
100 I = PRT
R = 100I / PT is the formula .