Six married couple are sitting in a room. Find the number of ways in which 4 people can be selected.
A couple is a group of two people (assuming they are all married)
We know that:
1. There are twelve people in total
Now, out of the four people, two have to form a couple.
This leaves us with 10 people that can fill the rest.
Out of the two we can pick out, the first can be any out of the 10.
The second person can't be the selected person's husband/wife.
This leaves us 8 people for the second choice.
There are 10×8 or 80 choices for one couple
Since there are six couples, we multiply 6 by 80
6×8=480 ways