There are three sections in a question paper, each containing 4 questions. If a candidate has to answer only 5 questions from this paper without leaving any section, then number of ways the candidate can make the choice of questions is

Step-by-step solution

Number of ways to select 5 questions from these sections as follows, A B C Section array lll 2 & 2 & 1 2 & 1 & 2 1 & 2 & 2 array gathered array lll 3 & 1 & 1 1 & 3 & 1 1 & 1 & 3 array . ^4 C₂ ^4 C₂ ^4 C₁ 3+ ^4 C₃ ^4 C₁ ^4 C₁ 3 4 ! 2 ! 2 ! 4 ! 2 ! 2 ! 4 ! 1 ! 3 ! 3+ 4 ! 3 ! 1 ! 4 ! 1 ! 3 ! 4 ! 1 ! 3 ! 3 432+192=624 gathered