Answer:
The answer is 8 years
Explanation:
FV= PV(1+r)^n
Where
PV= let's assume PV is $100
FV = Since FV will be doubled, the we have $200($100 x 2)
n= ?
r= 9percent
Let us use the rule of 72 which states that an investment will double when:
Annual Investment Rate x Number of Years = 72.
Number of years = 72/9
= 8 years
The investment is doubled in 8 years at the rate of 9percent
