Ramona deposited $4,190.51 into a savings account with an interest rate of 5.2% compounded twice a year. About how long will it take for the account to be worth $9,000?

A. 33 years, 5 months

B. 29 years, 9 months

C. 14 years, 11 months

D. 20 years, 8 months

Answer :

Kalahira
A = P(1+r/2)^2t A/P = (1+r/2)^2t ln(A/P) = 2t ln((1+r/2)) ln(A/P)/ln(1+r/2) =2t ln(9000/4190.51)/ln(1+0.052/2)=2t t=15 yrs therfore ans is C.14 years ,11 months