The population of a town 2 years ago was 62500. Since some persons migrate to different cities the number of people decreases every year at the rate of 4% per annum. Find its present population. 

17 Find the compound interest on Rs. 160000 for 2 years at 10% per annum when compounded semi-annually. 18 Find the compound interest on Rs. 125000 for 9 months at 8% per annum compounded quarterly. 20 The present population of a town is 12500 and it is increasing at the rate of 8% per annum. What will be the population of the town after 2 years? 1

Convert the following ratios to percentages.

(a) 3 : 4 (b) 2 : 3