Question

At what rate percent per year will a sum of money double it self in 15 year

Answer 1

`6.67\%`

Explanation:

we know that

The simple interest formula is equal to

`A=P(1+rt)`

where

A is the Final Investment Value

P is the Principal amount of money to be invested

r is the rate of interest

t is Number of Time Periods

in this problem we have

`t=15\ years\\ P=\$x\\ A=\$2x\\r=?`

substitute in the formula above

`\$2x=\$x(1+15r)`

simplify

`2=(1+15r)`

`15r=2-1`

`r=1/15=0.0667`

convert to percentage

`0.0667*100=6.67\%`