In a class, the average score of girls in an examination is 73 and that of boys is 71. The average score for the whole class is 71.8. The percentage of the girls in the class is :A.60%B.40%C.1.80%D.18%

1) 60
2) 40
3) 18
4) 70

• 73 g+71 b/ g+b = 71.8
  
  73 g + 71 b = 71.8(g+b)
  73 g - 71.8 g = 71.8 b - 71 b
  1.2 g = .8 b
  3 g = 2 b
  
  g=60
  b=40
  3:2
  boy=60
• 5 years agoHelpfull: Yes(1) No(0)
• 40%
  
  if there are g girls and total x students, then
  
  73g+71*(x-g)= 71.8x
  g/x = 2/5 =0.4
  so percentage of the girls in the class is 40%.
• 11 years agoHelpfull: Yes(0) No(0)