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?

• Total number of exams written by 100 students = 48 + 45 + 38 = 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.
• 8 years agoHelpfull: Yes(56) No(5)
• n(1)=48
  n(2)=45
  n(3)=38
  n(1U2U3)=100
  total appered in the exam= 48+45+38=131
  and 5 is given all three exam so,
  131-5=126
  100+x=126
  =>x=26
  so, 26 is answer
  
• 8 years agoHelpfull: Yes(9) No(5)
• For a group of three sets:
  1. n(A cup B cup C) = n(A) + n(B) + n(C) - n(A cap B) - n(A cap C) - n(B cap C) + n(A cap B cap C)
  now the required answer for this problem lies in the n(A cap B) - n(A cap C) - n(B cap C) part
  the answer coming out is 36
  but it is taken thrice
  so the answer is 12
• 8 years agoHelpfull: Yes(5) No(4)
• correct solution is
  Total number of exams written by 100 students = 48 + 45 + 38 = 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.
• 8 years agoHelpfull: Yes(4) No(3)
• total members writing exam=100
  total exams written=131+5 (who r writing all three exams)
  members writing two exams=131-100=31
  ans=31
• 8 years agoHelpfull: Yes(2) No(7)
• 100=n(f)+n(s)+n(t)-n(f inters)-n(s inter t)-n(t inter f)+n(f inter s inter t)
  =48+45+38-3(inter)+5
  3(inter)=136-100=36
  inter=12
• 8 years agoHelpfull: Yes(2) No(2)
• Answer is 16
  
  
• 8 years agoHelpfull: Yes(1) No(1)
• I+II+III exam = 48 + 45 + 38 = 131. All the three exams written by 5. That means one or two written by 131 - (5*3) = 116. Total members 100. So members writing two exams = 116-100 =16.
  
• 8 years agoHelpfull: Yes(1) No(3)
• 21 is the correct ans
• 8 years agoHelpfull: Yes(1) No(0)
• plz give me proper solution
• 8 years agoHelpfull: Yes(0) No(1)
• plz gie corrent ans
  
• 8 years agoHelpfull: Yes(0) No(1)
• 48+45+38+5-100=35
• 8 years agoHelpfull: Yes(0) No(2)
• For a group of three sets:
  1. n(A cup B cup C) = n(A) + n(B) + n(C) - n(A cap B) - n(A cap C) - n(B cap C) + n(A cap B cap C)
  now the required answer for this problem lies in the n(A cap B) - n(A cap C) - n(B cap C) part
  the answer coming out is 36
  but it is taken THRICE
  so the answer is 36/3=12
  
• 8 years agoHelpfull: Yes(0) No(2)
• total no. of exams written=48+45+38=131
  member are writing all three exam
  therefore, total exam written by five members=5*3=15
  left exams=131-15= 16 exams
  16 people are writing 2 exams
  
• 8 years agoHelpfull: Yes(0) No(4)
• 100 = 48+38+45 - (our solution) + 5
  our solution = 136-100 = 36.
• 8 years agoHelpfull: Yes(0) No(3)
• let X be number of persons writing first & second exam,
  Y be the no. of persons writing second & third exam,
  Z be no. of persons writing third & first exam
  Given 5 members are writing all the 3 exams.
  so, members who are writing first exam can be:
  X+Y+5=48 --> (1)
  likewise,
  for 2nd & 3rd:
  X+Z+5=45 -->(2)
  Y+Z+5=38 -->(3)
  solving 1,2,3 eq's, we get
  X=25, Y=18 , Z=15
  Total members who r writing 2 exams are:
  
  X+Y+Z=58
  
  
• 8 years agoHelpfull: Yes(0) No(3)
• 21 is correct answer @yashi das good explanitaion
• 4 years agoHelpfull: Yes(0) No(0)
• Total number of exams written by 100 students = 48 + 45 + 38 = 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.
• 1 year agoHelpfull: Yes(0) No(0)