In how much time compound money at compound interest of half yearly rate of Rs 800 will be Rs 926.10?

The sum for 2 years gives a compound interest of ₹ 3225 at 15 % rate. Then sum is 

There is 80% increase in amount in 5 years at simple interest. What will be the compound interest of Rs. 20,000 after 3 years at the same rate?

A sum borrowed under compound interest doubles itself in 10 years. When will it become fourfold of itself at the same rate of interest?

A person lent certain sum of money at 5% per annum simple interest and in 15 years the interest amounted to Rs 250 less than the sum lent. What was the sum lent (in Rs)?

Find the compound interest on a sum of Rs. 46875 for 2 years at 12% p.a, if interest is compounded 8 months?

If the difference of the compound interest and the simple interest on a sum of money for 3 years is Rs. 186. Find the sum of money, if the rate of interest in both cases be 10 % 

A sum of Rs.13,000 is to be paid back in 2 equal annual instalments. How much is each instalment if the interest is compounded annually at 8 % per annum?