If 64 amount to 83.20 in 2 years what will ₹ 86 amount to in 4 years at the same rate percent per annum? 

A sum of money amounts to 5,200 in 5 years and to 5,680 in 7 years at simple interest. The rate of interest per annum is-

A certain sum amounts to ₹15,500 in 2 years at 12% p.a. simple interest. The same sum will amount to what in$$1{1\over 2}$$ years at 10% p.a., if the interest is compounded half yearly (nearest to ₹1)?

What would be the simple interest obtained on an amount of `6,535 at the rate of 10 % p.a. (percent per annum) after 6 years?

What sum of money must be given as simple interest for six months at 4% per annum in order to earn 150 interest?

Rinky borrowed a certain sum of money from Kajal under the following repayment scheme based on simple interest. 8% p.a. for the initial 2 years, 9.5% p.a. for the next 4 years, 11% p.a. for the next 2 years, 12% p.a. after the first 8 years. Find the amount which a sum of Rs. 9000 taken for 12 years becomes at the end of 12 years?

At what rate per cent per annum will a sum of money double in 8 years?

A person invests a certain amount on simple interest. After 8 years he gets 16% interest. If he invests the same sum for 4 years, then he gets Rs. 9600 as interest, then the sum is