# In How many Years will the Amount become 16 Times

An amount invested in a certain scheme compounded annually doubles in 4 years. In how many years will the amount become 16 times when invested in the scheme.

- 12 years
- 16 years
- 18 years
- None of these

**Answer: (b) 16 years
Explanation:-**

Given that, Invest amount is doubled in = 4 years,

So after 4 years base amount will be twice of initial amount. After next 4 year (total 8 years) total amount will become 4 times and for next 4 years this amount will be the base amount and so on.

Therefore, Amount will be four times in 8 years;

and amount will be 4*2 =8 times in 12 years;

and 8*2 = 16 times in 16 years.