How many different teams of 11 players can be formed out of 17 players?

How many different committee of four members can be formed out of eight players?

How many types of matrices can be formed from 8 elements ?

How many types of matrices can be formed from 11 elements ?

In how many different ways can one invite 3 or more of his 6 friends?

How can we obtain different gases from air?

How many molecules of NADH are formed in one turn of Krebs' cycle?

How many words of four letter can be constructed by using the letters of the words CHEMISTRY(may not be meaningful)?

How many numbers of four digit can be formed out the digits 1,2,3,4,5,6 without repitition of digits?