Answer : 4 21 Explanation : Answer: D) 21 Explanation: Total number of exams written by 100 students = 48 45 38 = 131Now let us say x members are writing only 1 exam, y members are writing only 2 exams, z members are writing only 3 exams.Therefore, x 2y 3z = 131 also x y z = 100.Given that z = 5. So x 2y = 116 and x y = 95.Solving we get y = 21.So 21 members are writing exactly 2 exams.

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