A business manager wants to split her 20 staff members in groups of 5 to send them

for a project management training at a local university. She wants to know how

many possible groups (of 5) she can have.

1. Explain why she needs to find the number of combinations in this case.

She wants to calculate the possible number of groups of 5 by doing the following

calculation:

20!

(20 5)!

2. Explain, why the result above calculation is wrong.

3. Suggest the correct formula and find the number of combinations.