A group of 4 teachers,9 truckers, and 11 lawyers are going to form a committee of 2. How many different ways can the committee be formed with people from different professions?
We must break this into three cases:
1. A teacher and a trucker
4 ways to choose the teacher times 9 ways to
choose the trucker = 4×9 = 36 ways.
2. A teacher and a lawyer
4 ways to choose the teacher times 11 ways to
choose the lawyer = 4×11 = 44 ways.
3. A trucker and a lawyer
9 ways to choose the trucker times 11 ways to
choose the lawyer = 9×11 = 99 ways.
Total number of ways: 36 + 44 + 99 = 179 ways.
Edwin