Mean weight of 21 boys is 40Kg. If mean of the first 10 boys is 42 kg and that of last 10 boys is 38 kg. Find the weight of 11th boy
Answers
Answered by
0
Here is how I would GUESS at my first answer:
Boy Weight = 60 plus 10
Girl Weight = 60 minus 5
In order to balance the plus 10 boys, I am guessing that there must be twice as many girls
We need two numbers that add up to 150, one number double the other. What is one-third of 150?
GUESS: 50 boys, 100 girls
Be sure to double-check. Multiply 50 times 70; multiply 100 times 55; add those products; divide by 150. Did you get 60?
Boy Weight = 60 plus 10
Girl Weight = 60 minus 5
In order to balance the plus 10 boys, I am guessing that there must be twice as many girls
We need two numbers that add up to 150, one number double the other. What is one-third of 150?
GUESS: 50 boys, 100 girls
Be sure to double-check. Multiply 50 times 70; multiply 100 times 55; add those products; divide by 150. Did you get 60?
Similar questions