Eleven friends meet at a party. Each one shakes hand with each of the others once. The number of possible hand shakes is

There are 15 chairs in a row. Position of P is at the middle, and Q is at 12th position counting from the right. How many chairs are there between P and Q?

In a line of boys, Satish is 12th from right and 4th from left. How many boys should be included in this line so that their total number becomes 28?

Two numbers are in the ratio 3 : 5. If each number is increased by 10, the ratio becomes 5 : 7. The numbers are

If the simple interest on a sum of money at 5% per annum for 3 years is Rs. 1,200, find the compound interest on the same sum for the same period at the same rate.

Nitin is 7 ranks ahead of Joginder in a class of 39. If Joginder's rank is 17th from the last, what is Nitin's rank from the begining?