Question

Mark deposited $40,000 in an account that earns compound interest. the annual interest rate is 6%, and the interest is compounded 6 times a year. the current balance in the account is $40,400. how long has the money been invested?

Answer 1

A=p(1+i/m)^mn
40400=40000(1+0.06/2)^2n
40400/40000=(1.03)^2n
Log(40400/40000)=2n*log(1.03)
2n=log(40400/40000)/log(1.03)
N=0.2