The average age of all boys in the class is 16.66,while the average age of all girls in the same class is 18.75.Thus the average marks of all 40 students in the class is 17.5.what is the number of girls in the class?
(a)12(b)16(c)18(d)20 (e)data insufficient

• Its 16 my dear.....
  Its an very easy sum....
  
• 14 years agoHelpfull: Yes(8) No(14)
• e) data insufficient
• 14 years agoHelpfull: Yes(7) No(8)
• ans. e
• 14 years agoHelpfull: Yes(4) No(1)
• e)
• 14 years agoHelpfull: Yes(4) No(1)
• 16
• 14 years agoHelpfull: Yes(4) No(4)
• answer would b 16.
  total average = 17.5*40 = 700
  let number of girls be X , so number of boys will be 40-X
  => 16.66*(40-X) + 18.75*X = 700
  solving this equation you will find the number of girls as 16.
• 7 years agoHelpfull: Yes(2) No(1)