What sum will amount to Rs. 4913 in 18 months, if the rate of interest is 12% per annum, compounded half-yearly?

A shopkeeper allows 20% off on the marked price of goods and still gets a profit of 25%. What is the actual cost to him of an article marked Rs. 500?

Amit borrowed Rs. 16000 at 17 1/2 % per annum simple interest. On the same day, he lent it to Ashu at the same rate but compounded annually. What does he gain at the end of 2 years?

There is a continuous growth in population of a village at the rate of 5% per annum. If its present population is 9261, what it was 3 years ago?

The cost of a T.V. set was quoted Rs. 17000 at the beginning of 1999. In the beginning of 2000, the price was hiked by 5%. Because of decrease in demand the cost was reduced by 4% in the beginning of 2001. What was the cost of the T.V. set in 2001?