A sum of money invested at compound interest doubles itself in six years. In how many years will it become 64 times itself at the same rate of compound interest?

A sum of money invested at compound interest triples itself in five years. In how many years will it become 27 times itself at the same rate of compound interest ?

A sum of money placed at compound interest doubles itself in 6 years. In how many years will it amount to 16 times itself?

A sum of money placed at compound interest doubles itself in 3 years. In how many years will it amount to four times itself?

A sum of money placed at compound interest doubles itself in 4 years. In how many years will it amount to four times itself?

A sum of money placed at compound interest doubles itself in 4 years. In how many years will it amount to eight times itself ?

A sum of money placed at com pound interest doubles itself in 4 years. In how many years will it amount to four times itself ?

A sum of money doubles itself at compound interest in 4 years. In how many years will it become 8 times?

A sum of money at compound interest amounts thrice of itself in 3 years. In how many years it will be 9 times of itself ?