Question

In how many ways a team of 3 boys and 3 girls can be formed from 10 boys and 5 girls, if two particular B₁ and B₂ are not in team together:

(1) 1115

(2) 1120

(3) 1280

(4) 1220

Answer 1

Correct option is (2) 1120

Total no. of way to select 3 boys and 3 girls = ¹⁰C₃ - ⁵C₃ = 1200

When particular boys B₁ and B₂ both are in team = ⁸C₁.⁵C₃ = 80

So required number of ways = 1200 - 80 = 1120