Q11 The simple interest on certain sum for 2 years is Rs.160 and compound interest at same rate of interest is Rs.168. What is the sum & Rate of interest?

Q12 A person lent out a certain sum on simple interest and the same sum on compound interest at a certain rate of interest per annum. He noticed that the ratio between the difference of compound interest and simple interest of 3 years and that of 2 years is 25 : 8. The rate of interest per annum is

Q13 My cousin lends me Rs.10 lakhs for studying in United States at 8% compound interest per annum, during the course period of 2 years and at 12% per annum after completion of my studies. If I return 50% of the amount which is to be returned on completion of studies, and the remaining after one year, how much interest must I pay him during the whole period in Lakhs?

Q14 A bank pays interest @ 8 percent p.a. on a deposit for half a quarter as well as on a deposit for one quarter. A makes a deposit of Rs.25 lakhs for a quarter. B makes a deposit of Rs.25 lakhs for half a quarter, and after maturity reinvests the entire amount for half a quarter. What is B’s gain over A?

Q15 The least number of complete years in which a sum of money put out at 20% compound interest will be more than doubled is: