The average weight of a group of boys is 20 kg.
The average weight of a group of boys is 20 kg. After a boy of weight 34 kg joins the group, the average weight of the group goes up by 1 kg. Find the number of boys in the group originally ?
Answer/Solution
13
Steps/Work
Let the number off boys in the group originally be x.
Total weight of the boys = 20x
After the boy weighing 34 kg joins the group, total weight of boys = 20x + 34
So 20x + 34 = 21(x + 1) = > x = 13.
ANSWER:D
Total weight of the boys = 20x
After the boy weighing 34 kg joins the group, total weight of boys = 20x + 34
So 20x + 34 = 21(x + 1) = > x = 13.
ANSWER:D