Damager wrote:

If a committee of 3 people is to be selected from among 5 married couples so that the

committee does not include two people who are married to each other, how many such

committees are possible?

A. 20

B. 40

C. 50

D. 80

E. 120

Total number of ways to select 3 out of 10=10C3=120

Combination with each couples 8C1 = 8

Total 5 couples 8*5=40

Combi with no couples = 120-40=80

Sorry, the part written in red is not clear. Please explain it. Thanks.

The red colored line represents all possible ways of selecting the third person in the committee aft a couple has been selected. So we need to select 1 person from the remaining 8.