Total 100 members are writing exam. In the 48 members are writing first exam. 45 members are writing second exam. 38 members are writing third exam. 5 members are writing all the three exams. How many members are writing 2 exams?
Choices:	A) 66	B) 21	C) 88	D) 719	E) 011
otal number of exams written by 100 students = 48 + 45 + 38= 
<gadget id="calculator">48 + 45 + 38</gadget>
<output>131</output>
131   Now 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.   Answer:21
<result>B</result>
Total 100 members are writing exam. In the 48 members are writing first exam. 45 members are writing second exam. 38 members are writing third exam. 5 members are writing all the three exams. How many members are writing 2 exams?