If a secretary and a joint secretary are to be selected from a committee of 11 members, then in how many ways can they be selected ?

In how many ways can 6 members the selected from a group of 10 members ?

In how many ways can 2 doors be selected from 3 doors ?

A committee of 2 boys is to be selected from 4 boys. In how many ways can this be done ?

A committee of 2 boys is to be selected from 4 boys. In how many ways can this be done ?

In how many ways can a chairman and vice - chairman be elected from a committee of 8 members who are equally eligible for the post ?

In how many ways a committee of 7 members can be selected from 10 members ?

In how many ways a committee of 7 members can be selected from 10 members ?

There are 3 nominations for the post of president, 4 for the post of vice-president and 5 for the secretary. i. In how many ways can candidates be selected for each of these posts? ii. In how many ways can any one of these posts be filled?

There are 6 boys and 3 girls in a class. An entertainment committee of 6 persons is to be selected such that there are 4 boys and 2 girls in the committee. In how many ways can the committee be selected?

A committee of 5 members is going to be formed from 3 trainees, 4 professors and 6 research associates. How many ways can they be selected, if in committee, there are 2 trainees and 3 research associates?