In a class the average weight of 150 students is 80 kg. The average weight of boys and girls is 85 kg and 70 kg respectively. The number of girls in the class is

• 50 no of girls
  
• 9 years agoHelpfull: Yes(0) No(0)
• Avg weight of 150 students =150*80=12000
  avg weight of boys=85x(suppose no of boys as x)
  than no of girls are 150-x
  avg weight of girls=(150-x)*70
  now, 85x+(150-x)*70=12000
  so x=100 and girls 50
• 9 years agoHelpfull: Yes(0) No(0)
• Total wt is 150*80=12000
  100 no wt with average of 85=8500
  So the number of girls with an average of 70=50
• 7 years agoHelpfull: Yes(0) No(0)