Answer
315 four-person committees can be formed if two people must be teachers and two people must be parents
Explanation
The number of teachers = 6
The number of parents = 7
The number of required teachers to be formed = 2
The number of required parents to be formed = 2
The number of four-person committees that can be formed =
⁶C₂ x ⁷C₂ = 15 x 21 = 315
∴ 315 four-person committees can be formed if two people must be teachers and two people must be parents
