Question 62
A sum of money becomes 3 times in 10 years at the rate of compoundinterest (compounded annually). In how many years will it become 81 times?
Solution
amount with compound interest = $$P(1+\frac{R}{100})^n$$
3P= $$P(1+\frac{R}{100})^{10} $$
3= $$(1+\frac{R}{100})^{10}$$ ->( 1)
amount with compound interest = $$P(1+\frac{R}{100})^n$$
81P= $$P(1+\frac{R}{100})^T$$
$$3^4$$ =$$(1+\frac{R}{100})^T$$ ->( 2)
Equating both the equations
$$((1+\frac{R}{100})^ {10})^4$$ =$$(1+\frac{R}{100})^T$$
T = 40 years
Create a FREE account and get:
- Free SSC Study Material - 18000 Questions
- 230+ SSC previous papers with solutions PDF
- 100+ SSC Online Tests for Free
