Solution
I think the interest is compounded yearly, if so
First, convert R as a percent to r as a decimal
r = R/100
r = 6.25/100
r = 0.0625 per year
A = 10000
P = 5000
[tex]A=P(1+\frac{r}{n})^{nt}[/tex][tex]\begin{gathered} 10000=5000(1+6.25)^t \\ \frac{10000}{5000}=(1+0.0625)^t \\ 2=(1.0625)^t \\ \ln 2=\ln (1.0625)^t \\ t=11.5 \end{gathered}[/tex]
Use logarithms or a scientific calculator
t = 11.5
In 11.5 years $5000 investment be worth of $10000
>>>>>>>>>>>>>
In case the interest is simple interest
Interest = Amount - Principal = $10000-$5000 = $5000
Time = 100*Interest / (Principal*Rate
= 100*5000 / (5000*6.25)
t = 16 years
In 16 years $5000 investment be worth of $10000
