AP EAPCET 08-Jul-2022 Shift 1 Paper

(a) Case I
When one question is selected from Section A, then there are 4 ways of selecting question from Section B i.e it can be selected either 1 question or 2 questions or 3 questions or 4 questions.
The number of ways when one question from Section A is selected
=3C1(4C1+4C2+4C3+4C4)
=3(4+6+4+1)
Similarly, the number of ways when two questions are selected from Section A
=3C3(4C1+4C2+4C3+4C4)
=3(4+6+4+1)=45
The number of ways when three questions are selected from Section A
=3C3(4C1+4C2+4C3+4C4)
=1(4+6+4+1)=15
∴ The required number of ways
=45+45+15=105