A sum of Rs. 12,000, deposited at compoundd interest becomes double after 5 years. How much will it be after 20 years ?
For compound interest A = $$p(1+\frac{r}{100})^{n}$$ where p is principal amount, r is rate and t is time
after 5 years it gets doubled
hence putting the values we will get $$(1+\frac{r}{100})^{5}$$ = 2
now after 20 years total amount will be $$p((1+\frac{r}{100})^{5})^{4}$$ = 16p = $$16 \times 12000$$ = 192000
Create a FREE account and get: