In a class of 80 students. 60% participate in games and the rest do not. The average weight of the former group is 5% more than that of the latter. If the average weight of all the students is 51 1/2 kg, then what is the average weight (in kg)of the former group?.
Answers
Answered by
9
The average weight (in kg)of the former group is 52.55kg.
Given, total strength of class = 80.
60% participate in games.
So, no. of people participating in games = 60% of 80 = 48
Rest do not participate.
People not participating = 80 - 48 = 32
The average weight of the group with 48 peopleis 5% more than the average weight of the group with 32 people.
Let the average weight of 48 people group be x.
Total weight = 48x
So, avg. weight of 32 people group is (x-0.05x) = 0.95x
Total weight = 32(0.95x) = 30.4x
Total weight of 80 students = 48x + 30.4x = 78.4x
Average, weight of 80 students = 51.5 kg.
So, total weight of 80 students = 4120 kg.
Thus, 78.4x = 4120
x = 4120/78.4 = 52.55kg
This the average weight.
Similar questions