Indian Institute of Foreign Trade 2012 Solved Paper

There are 3 ways in which she can answer the questions:-
1. 3 from group 1 and 3 from group 2
She can select 3 questions from each group in ${}_{}^5{\mathit{C}}_3^{}$ ways and thus the total number of ways ${=}^5{\mathit{C}}_3{\times }^5{\mathit{C}}_2=100$
2. 4 questions from group 1 and 2 questions from group 2
She can select 4 questions from group 1 in 5 ways and 2 questions from group 2 in 10 ways and thus, total number of ways = 50
Same will be the case for 4 questions from group 2 and 2 questions from group 1
Thus, the total number of ways $=100+50+50=200$
Hence, option C is the correct answer.