A group of 5 friends wants to form a team of 3 for a sports event. However, two specific friends, Mark and Sarah, refuse to be on the team together. In how many ways can the team be formed?
20
84
12
16
Number of friends
Number of friends to be selected
Number of ways to select 3 friends from 5 without Mark and Sarah together:
Selecting Mark:
We need to select 2 more friends from the remaining 4 (excluding Mark and Sarah). This can be done in ways.
Selecting Sarah:
Similarly, we need to select 2 more friends from the remaining 4 (excluding Mark and Sarah). This can also be done in ways.
Hence option 3 is correct.
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