The average age of students in a class is 16.when a teacher of age 40 is added , the average becoems 17. what is the total number of students

• ANSWER 23
  Avg age=16
  Total student = x
  Sum of All age = 16x
  add teacher age 16x+40
  avg of all 16x+40/x+1 = 17
  16x+40 = 17x+17
  x=23
  Total number of Students is 23
• 12 years agoHelpfull: Yes(18) No(1)
• 40 is correct answer
• 6 years agoHelpfull: Yes(0) No(0)
• given,
  total sum of age of student(x)/total no. of studnets(n) =16----(i)
  (x+teacher's age(40))/(n+1)=17-------(ii),here n+1=no.of student(n) + teacher(1)
  
  from (i) x=16n
  from (ii) x+40=17(n+1)
  16n+40=17n+17
  40-17=17n-16n
  23=n
  n=23
  number of student =23
• 4 years agoHelpfull: Yes(0) No(0)