Answers

2014-08-10T20:18:39+05:30
A = P (1 +  \frac{r}{100} )^{t} \\  \\ 2P = P (1 +  \frac{r}{100} )^{15} ...(1)\\  \\ 8P = P (1 +  \frac{r}{100} )^{T} ...(2)

take log of both the equations
log_e2 = 15 * log_e(1 +  \frac{r}{100}) ...(3) \\  \\ log_e8 = T * log_e(1 +  \frac{r}{100}) \\ 3log_e2 = T * log_e(1 +  \frac{r}{100}) ...(4)

Divide eq.(4) by eq.(3)
3 =  \frac{T}{15} -> T = 45

Answer
45 years
0
2014-08-10T20:30:02+05:30

This Is a Certified Answer

×
Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
 2 P  = P ( 1 + r )^15

(1+r)^15 = 2            take cube on both sides

(1=r)^45 = 2³ = 8
So  P (1 - r)^45  = 8 P

SO  Principal amounts to 8 times original amount in 45 years

1 5 1
excuse me.. will u explain the last step little clearly?? So P (1 - r)^45 = 8 P
... this step