WAEC Further Mathematics 2021 Question 27

Question 27

Permutations and Combinations

A committee consists of 6 boys and 4 girls. In how many ways can a sub-committee consisting of 3 boys and 2 girls be formed if one particular boy and one particular girl must be on the sub-committee?

A.120
B.80
C.56
D.30

Show the answer and explanation

Answer: D (30)

Explanation

Choose the other 2 boys from 5 and the other girl from 3: ⁵C₂ × ³C₁ = 10 × 3 = 30.