# The mean weigt of 60 students is 40 kg. If the mean weight of boys is 50 kg, while that of girls is 30 kg. Find the numbers of boys and girls.

1
by Coolaks

## Answers

2016-03-20T22:06:58+05:30

### This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
Let the number of boys be 'x'
and girls in the school be 'y'.
therefore x + y = 60
since mean = sum of observations by no of observation

50*x + 30*y / x + y = 40
50x + 30y = 40*60
50x + 30y = 2400
5x + 3y = 2400/10 = 240

so we have 5x + 3y = 240 and x + y = 60
multiplying second equation by 3 , we get ,
5x + 3y =240
3x + 3y = 180
by subtracting , y terms will be cancelled , and
2x = 60
x = 30

substituting x in 2nd equation , we get,

30 + y = 60
y =  60 - 30 = 30
hence x = 30 and y = 30
plz mark brainliest
mark brainliest
mrk brainliest