A student is required to answer 6 out of 10 questions divided into two groups each containing 5 questions. He is not permitted to attempt more than 4 from each group. In how many ways can he make the choice?

Answer: Option D

Number of ways of choosing 6 from 10 = ¹⁰C₆ = 210
Number of ways of attempting more than 4 from a group,
= 2 × ⁵C₅ × ⁵C₁
= 10
Required number of ways
= 210 - 10
= 200