In a group of 12 students, the average weight
per student is 43 kg. If two students A & B hav-
ing weights 48 kg & 34 kg. leave the group and a
teacher 'T' joins the group, the average weight of
a member of group becomes 45 kg. What is the
weight of the teacher ?
Answers
Answered by
2
The weight of teacher is 61 kg
1) The number of students in group = 12.
Average weight of group = 43 kg.
Sum of weights of students = 43*12 = 516 kg.
2) Weight of students who left the group is 48 and 34 kg.
Remaining sum of weight = 516 - 48 -34 = 434 kg
Remaining number of students = 12-2 = 10
3) Let the weight of new teacher be x.
New sum of weight = 434+x kg
New total of people in group = 10+1 = 11.
4) Average weight of group = (434+x)/11 kg
Given average of group = 45 kg
Equating both and solving for x
(434+x)/11 = 45
x = 495-434 = 61 kg
Similar questions