SOLUTION: the ratio of boys to girls in a class is 4 to 3, and there is a total of 28 students. how many girls are in the class?

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Question 672871: the ratio of boys to girls in a class is 4 to 3, and there is a total of 28 students. how many girls are in the class?
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!

let x be girls and y boys
the ratio of boys to girls in a class is 4%3A3,
y%3Ax=4%3A3......solve for x
3y=4x
y=%284%2F3%29x......eq. 1

and there is a total of 28, which is x%2By=28...substitute y from eq. 1
%284%2F3%29x%2Bx=28....solve for y
%284%2F3%293x%2B3x=28%2A3
4x%2B3x=84
7x=84
x=84%2F7

highlight%28x=12%29......girls


y=%284%2F3%29x......eq. 1....plug in x
y=%284%2F3%2912
y=%284%2Fcross%283%29%29cross%2812%294
y=4%2A4
highlight%28y=16%29
so, there are highlight%2816%29 boys and highlight%2812%29 girls in the class