Question

Question 21 (4 points)

Answer 1

Step-by-step explanation:

There are ₉C₂ ways to choose 2 students from 9.

There are ₁₅C₂ ways to choose 2 teachers from 15.

There are ₂₄C₄ ways to choose 4 people from 24.

Therefore, the probability is:

P = ₉C₂ ₁₅C₂ / ₂₄C₄

P = 36 × 105 / 10626

P ≈ 0.356