SOLUTION: In a class, the number of boys and girls are in ratio 3:2. In a test, the mean score for boys is 70 while the mean score for the whole class is 76. The mean score for girls is ?
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Question 960892: In a class, the number of boys and girls are in ratio 3:2. In a test, the mean score for boys is 70 while the mean score for the whole class is 76. The mean score for girls is ? Answer by ankor@dixie-net.com(22740) (Show Source):
You can put this solution on YOUR website! In a class, the number of boys and girls are in ratio 3:2.
Let x = the multiplier
then
3x = no. of boys
2x = no. of girls
and
5x = total in the class
:
In a test, the mean score for boys is 70 while the mean score for the whole class is 76.
The total of all the boys scores = 3x(70) = 210x
The total of all the student scores = 5x(76) = 380x
:
" The mean score for girls is ?"
let g = the av girls' score
then
2xg = the total of the girls score
:
boys total + girls total = class total
210x + 2gx = 380x
divide thru by x
210 + 2g = 380
2g = 380 - 210
2g = 170
g = 170/2
g = 85% is the average score of the girls
