How many integers, greater than 999 but not greater than 4000, can be formed with the digits 0, 1, 2, 3 and 4 if repetit…

In a hockey championship, there are 153 matches played. Every two team played one match with each other. The number of t…

From 6 men and 4 ladies, a committee of 5 is to be formed. In how many ways can this be done, if the committee is to inc…

In how many different ways can the letters of the word AWARE be arranged?

In how many ways can the letters of the word 'LEADER' be arranged?

How many numbers are there between 100 and 1000 such that at least one of their digits is 6?

In how many different ways can the letters of the word OPERATE be arranged?

In how many ways 2 students can be chosen from the class of 20 students?