Total number of questions =13 Now of questions to be selected =10 Restriction - At least 4 from first 5 questions are to be selected. Case I: If exactly 4 out of first 5 questions are selected. Number of ways of selecting 4 questions from 5 questions =5C4=5 Remaining 10−4=6 questions are selected from last 13−5=8 questions in 8C6 ways ∴ Number of ways =5×8C6=140 Case II: If exactly 5 out of first 5 questions are selected. Number of ways of selecting 5 out of 5 questions =5C5=1 Remaining 10−5=5 questions are selected from last 13−5=8 questions in 8C5 ways. ∴ Number of ways =1×8C5=56 ∴ Total number of ways =140+56=196