Question

Quantity
I. A sum of money becomes double in 4 years at compound interest, compounded annually. In how many years it will become 9 times? Quantity
II. A sum of money tripled itself in 20 years at a certain rate of interest. In how many years the amount would have been 1.5 times of itself at the same rate of interest?

Q: Answer-Quantity I. A sum of money becomes double in 4 years at compound interest, compounded annually. In h...

Quantity I. A p 1R100 t 3P P 1R100 4 3 1 R100 4 i A p 1R100 t 9P P 1R100 t 32 1 R100 t .ii From i and ii 1R100 4 2 1R100 t t 8 years Quantity II. Since the amount was Rs 100. It becomes Rs 300 in 20 years. Rs 300 Rs 100 Rs 200 interest In 20 years, interest is Rs 200 In 1 year, the interest is Rs20020 Rate of interest 10 per annum. 100 x 50 100 x 10 5 years Hence Quantity I Quantity II