Question

Adam put $100 in a savings account. After 10 years, he had $1649 in the account. What rate of interest did he earn? Use the formula A = Pert, where A is the ending amount, P is the principal (initial amount), r is the interest rate, and t is time.

Answer 1

The formula is
A=p e^rt
A future value 1649
P present value 100
R interest rate?
T time 10 years
E constant
Solve the formula for r
R=[log (A/p)÷log (e)]÷t
R=(log(1,649÷100)÷log(e))÷10
R=0.28×100
R=28%