A man has 9 friends: 4 boys and 5 girls. In how many ways can he invite them, if there have to be exactly 3 girls in the invitees?

- 80
- 160
- 200
- 320

**Answer**

Out of the 5 girls, 3 girls can be invited in ^{5}C_{3} ways.

He can invite one, two, three, four or even no boys. Out of 4 boys, he can invite them in the said manner in (2)^{4} ways.

Thus, the total number of ways is ^{5}C_{3} × (2)^{4} = 10 × 16 = 160.

**The correct option is B.**