Question

About (a) A manager must select three coders from her group to write three different software projects. There are 7 junior and 3 senior coders in her group. The first project can be written by any of the coders. The second project must be written by a senior person and the third project must be written by a junior person. How many ways are there for her to assign the three coders to the projects if no person can be assigned to more than one project?

Answer 1

Answer:

There are 168 ways to assign three coders to the 03 projects as described in the question.

Explanation:

- If the first project is assigned to Junior coder:

  + There are 7 ways to assign for First Project;

  + There are 3 ways to assign for Second Project;

  + There are 6 ways (7-1) to assign for Third Project.

=> There are 7 x 3 x 6 = 126 ways in total for assigning coders to 03 projects given the First project is assigned to Junior coder.

- If the first project is assigned to Senior Coder:

  + There are 3 ways to assign for First Project;

  + There are 2 ways (3-1) ways to assign for Second Project;

  + There are 7 ways to assign for the Third Project.

=> There are 3 x 2 x 7 = 42 ways in total for assigning coders to 03 projects given the First project is assigned to Senior coder.

- In total, there are 126 + 42 = 168 ways to assign three coders to the 03 projects as described in the question.

Answer 2

Answer:

168 ways .

Explanation: