In a class of 52 students the number of boys is two less than the number of girls. Average weight of the boys is 42 kg, while the average weight of all the 52 students is 40 kg. What is the approx. average weight of the girls.
1. 38 kg
2. 39 kg
3. 40 kg
4. 42 kg

• girls=x
  boys=x-2
  x+x-2=52 ==> x=27
  
  girls= 27
  boys = 25
  avg of boys
  => sum of boys weight/25 = 42
  => sum of boys weight=1050
  avg of girls
  => sum of students weight/52 = 40
  => sum of students weight=2080
  sum of girls weight = sum of students weight-sum of boys weight
  sum of girls weight = 2080-1050 = 1030
  
  avg of girls weight = 1030/27 = 38.1(approximately)
  ans = 38 kg
• 11 years agoHelpfull: Yes(14) No(0)
• girls=x
  boys=x-2
  x+x-2=52 ==> x=27
  
  girls= 27
  boys = 25
  avg of boys
  => sum of boys weight/25 = 42
  => sum of boys weight=1030
  avg of girls
  => sum of students weight/52 = 40
  => sum of students weight=2080
  sum of girls weight = sum of students weight-sum of boys weight
  sum of girls weight = 2080-1030 = 1050
  
  avg of girls weight = 1050/27 = 38.1(approximately)
  ans = 38 kg
• 11 years agoHelpfull: Yes(5) No(2)
• 39
  replace above given aans whr 25*42=1050
• 11 years agoHelpfull: Yes(4) No(4)
• avg wt of total class= (avg wt of boys +avg wt of girls)/2
  40=(42+x)/2
  80=42+x
  x=38
• 7 years agoHelpfull: Yes(1) No(0)