Q1: The average age of 10 students in a class increases by 4.8 months when a boy of age 6 yrs is replaced by a new boy. What is the age of the new boy.

• 10 years
  Total increase in age of 10 students= 10*4.8=48 months= 4 years
  Age of a new boy should be 4 year more than the boy who is replaced.
  age of the new boy=6+4= 10 years
• 10 years agoHelpfull: Yes(5) No(0)
• if 6 age boy replaced so
  new boy age is 6 yr + 4.8 * 10 months
  which is 6 + 4 = 10yr
  so ans is 10yr
• 10 years agoHelpfull: Yes(0) No(0)
• let x/10=y
  new boy age=a
  x-6+a/10=y+4.8(months)
  so
  a-6/10=4.8mounths
  a-6=48months
  =>a-6=4years
  a=6+4=>10years
• 6 years agoHelpfull: Yes(0) No(0)
• sum/10 = avg
  (sum-6years +new)/10 = avg+4.8m
  replace avg with 1st equation
  (sum-6years +new)/10=sum/10 + 4.8m
  new -6years = 48months
  new = 4y +6y
  new=10 years
• 6 years agoHelpfull: Yes(0) No(0)