Question

a sum of money invested at Compound interest becomes 27 times of itself in 6 years. in how many years it will become 81 times of itself at the same rate of interest?​

Answer 1

Since it is compound interest, the Principal for the second year would be 2P. This again doubles itself in another year because Interest rate is 100%. So at the end of two years it becomes 4 P. Hence at an interest rate of 100% , the sum of money becomes 4 times itself.