Permutations and Combinations Questions - Permutation and Combinations

21:

In a factory for five jobs the members A, B, C, D, E are eligible.

In how many ways the first two jobs can be filled?

 A. 20 B. 30 C. 60 D. 120 Answer Report Discuss Option: A Explanation : First job can be filled in 5 ways by anyone of the five numbers. Out of the five, if one is selected for the first job, then second job can be filled by the remaining 4 members in 4 ways. Hence number of ways of filling the first and second jobs = 5 x 4 = 20 Click on Discuss to view users comments. Write your comments here:
22:
In a factory for five jobs the members A, B, C, D, E are eligible.

All jobs can be filled in hcw many ways?

 A. 20 B. 40 C. 60 D. 120 Answer Report Discuss Option: D Explanation : 5 jobs can be filled by 5 members in  5P5 ways.  5P5 = 5 ! = 5 x 4 x 3 x 2 x 1  = 120 ways. Click on Discuss to view users comments. Write your comments here:
23:

If 6 identical coins are arranged in a row, then number of arrangements in which 4 are heads and 2 are tails are

 A. 4 B. 6 C. 12 D. 15 Answer Report Discuss Option: D Explanation : Click on Discuss to view users comments. Write your comments here:
24:

l'here are four bus lines between A and B; and three bus lines between Band C.

The number of ways a person can travel by bus from A to C by way of B will be

 A. 10 B. 12 C. 14 D. 24 Answer Report Discuss Option: B Explanation : There are four ways to go from A to B and three ways to go from B to C, Hence there are 4 / 3 = 12 ways to go from A to C by way ofR Click on Discuss to view users comments. Write your comments here:
25:

The number of ways in which a team of eleven players can be selected from 22 players including 2 of them and excluding 4 of them is

 A. 16C11 B. 16C5 C. 16C9 D. 20C9 Answer Report Discuss Option: C Explanation : Click on Discuss to view users comments. Write your comments here: