R = 8.5%/year
Equation:
r = (1/t)(A/P - 1)
Calculation:
Solving our equation
r = (1/2)((20475/17500) - 1) = 0.085
r = 0.085
converting r decimal to a percentage
R = 0.085 * 100 = 8.5%/year
The interest rate required to get
a total amount, principal plus interest, of $ 20,475.00
from simple interest on a principal of $ 17,500.00
over 2 years is 8.5% per year.