Let's denote the total number of men as M and the total number of women as W.
The problem is to select 3 men and 2 women such that one specific man and one
specific woman are always selected. Step 1: Since one man is always selected,
we need to select the remaining 2 men from the remaining M-1 men.
Number of ways to select 2 men out of (M-1) men = (M−12)\binom{M-1}{2}(2M−1)
Step 2: Similarly, since one woman is always selected, we need to select the
remaining 1 woman from the remaining W-1 women.
Number of ways to select 1 woman out of (W-1) women =
(W−11)\binom{W-1}{1}(1W−1) Step 3: Multiply the results from Step 1 and Step
2 to get the total number of ways:
(M−12)×(W−11)\binom{M-1}{2}\times \binom{W-1}{1}(2M−1)×(1W−1) From the
sources, a similar example states the number of ways to select is
(42)×(51)=30\binom{4}{2}\times \binom{5}{1}=30(24)×(15)=30 when 3 men and 2
women are selected such that one man and one woman are always selected
(assuming 5 men and 6 women total, for instance). So the formula and logic
apply as above. If you provide the total number of men and women, I can
calculate the exact number for you. Without those numbers, the general formula
is: Number of ways = (M−12)×(W−11)\binom{M-1}{2}\times
\binom{W-1}{1}(2M−1)×(1W−1) For example, if total men = 5 and total women =
6,
Number of ways = (42)×(51)=6×5=30\binom{4}{2}\times \binom{5}{1}=6\times
5=30(24)×(15)=6×5=30 ways. This matches the standard answer for this type of
problem. Thus, the number of ways to select 3 men and 2 women such that a
particular man and a particular woman are always selected is
(M−12)×(W−11)\binom{M-1}{2}\times \binom{W-1}{1}(2M−1)×(1W−1). If M=5 and
W=6, this equals 30 ways.
what are the number of ways to select 3 men and 2 women such that one man and one woman are always selected?
