Guided Example #2 - Factorials, Combination, Permutation
In a company there are seven executives: four women and three men. Three are selected to attend a seminar. Find the probability that one man and two women will be selected.
A. 335 B. 635 C. 1835 D. 1235
Step 1
Let's start by finding the sample space. There are seven people and we are picking 3 of them.
This can be done in
C73=7!(3!)(4!)=35 ways.
Step 2
There are 3 ways to pick one man out of 3(C31=3) and 6 ways (C42=6) to pick 2 women out of 4.
So the desired probability is
P=C31C42C73=(3)(6)35=1835.
All Steps
Let's start by finding the sample space. There are seven people and we are picking 3 of them.
This can be done in
C73=7!(3!)(4!)=35 ways.
There are 3 ways to pick one man out of 3(C31=3) and 6 ways (C42=6) to pick 2 women out of 4.
So the desired probability is
P=C31C42C73=(3)(6)35=1835.