A sum of money at compound interest amounts to twice itself in four years. In how many years will it be four times itself?
18
12
8
6
Data insufficient
A=P(1+r100)n
2P=P(1+r100)4
Now, 4P=P(1+r100)n
Thus, n=8
A sum of money triples itself at compound interest in 12 years. In how many years will it become 9 times?
A sum of money doubles itself in 3 years at compound interest, when the interest is compounded annually.In how many years will the sum amount to 16 times of itself?