The simple interest on Rs. 12000 at a certain rate of interest in five years is Rs. 7200. Find the compound interest on the same amount for five years at the same rate of interest.

Rakesh invests Rs. 8000 at some rate of interest. Being simple interest the  money doubles in 5 years. Raj sees this and invests Rs. 6250 for 3 years at the same rate of interest. How much interest does Raj get?

A article is marked at Rs. 65 and a customer buys it for Rs. 56.16 and got two successive discount of 4% and k%. Find the value of   k?

A person bought two watches for Rs. 480. He sold one at a loss of 15% and the other at a profit of 19% and he found that each watch was sold at the same price. Find the cost price of the two watches.

Vikram gives 35% of the money he had to his wife and gave 50% of the money he had to his sons. Remaining amount of Rs. 11,250 he kept for himself. What was the total amount of money Vikram had?

Milk and water are mixed in vessel A in the ratio of 5:2 and in vessel B in the ratio of 8:5. In what ratio should quantities be taken from the two vessels so as to form a mixture in which milk and water will be in the ratio of 9:4 ?

3 year ago, the average age of a family of 5 members was 17 years. A baby having been born, the average age of the family is the same today. The present age of the baby is:

The average age of 30 students is 9 years. If the age of their teacher is included, the average age become 10 years. The age of the teacher ( in years ) is