Hi adkikani,
We're told that an office has 6 employees (5 female employees and 1 male employee). We're asked for the number of ways that a 3-person committee can be created if the committee must include the male employee. This question can be treated as either a Permutation OR a Combination (depending on how you want to do the math). In addition, since the number of options is relatively small, you could 'brute force' the solution by writing out all of the possibilities.
Since we're forming a 'group', the order of the 3 people does NOT matter. Thus, using the Combination Formula would make sense. The one male employee would take that one 'spot', leaving the 5 female employees for the remaining 2 spots.... 5c2 = (5!)/(2!)(3!) = (5)(4)/(2)(1) = 10 possible groups.
After placing the one male employee, you could do the rest of the calculation as a Permutation. However, you have to realize that a Permutation will create "duplicate" groups - and we will have to remove those duplicates.
5 women for the 1st spot
4 women for the 2nd spot
(1)(5)(4) = 20.... however, each group in there has been counted twice (since the pair A,B is the same as the pair B,A). Thus, we have to divide this total by 2... 20/2 = 10 groups.
Final Answer:
GMAT assassins aren't born, they're made,
Rich