1. A certain principal is invested in a scheme of compound interest. The amount obtained after 1 year is Rs 2400 and the amount obtained after 2 years is Rs 2880. What is the rate of interest (in percentage)?
2. For an amount, simple interest at the rate of interest of 12% per annum for 6 years is Rs 25920. What will be the compound interest (in Rs) on same amount at the rate of interest of 8% per annum compounding annually for 2 years?
4. A person lent Rs 10000 to B for 3 years and Rs 6000 to C for 4 years on simple interest at same rate of interest and received Rs 5400 in all from both of them as interest. What is the rate of interest (in %)?
5. The difference of compound interest and simple interest for 3 years and for 2 years are in ratio 23 : 7 respectively. What is rate of interest per annum (in %)?
6. The difference between compound interest and simple interest on a sum for 2 year at 20% per annum is Rs 200. If the interest is compounded half yearly, then what is the difference (in Rs) between compound and simple interest for 1st year?
9. Rohan borrowed a certain sum of money at simple interest. Rate of interest was 3% per annum for first 3 years, 4% per annum for next 5 years and 6% per annum for next 7 years. If he paid Rs 2059 as interest, then what is the sum borrowed (in Rs)?
10. The difference between simple and compound interests compounded annually on a certain sum of money for 2 years at 9% per annum is Rs 405. The sum is ______ .