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.

Question

Sonia Mendez

Mathematics

13 September, 18:18

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.

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Bridger Mclean · 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%