SOLUTION: The number of boys in a class is 4 more than the number of girls. The ratio of the number of boys to the number of girls is 7/5. How many students are there in class?

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Question 696747: The number of boys in a class is 4 more than the number of girls. The ratio of the number of boys to the number of girls is 7/5. How many students are there in class?
Answer by Stitch(470) About Me  (Show Source):
You can put this solution on YOUR website!
Let B = number of Boys
Let G = number of girls
Equation 1: B+=+G+%2B+4
Equation 2: B%2FG+=+7%2F5
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Plug (G + 4) into equation 2 for B
Equation 2: B%2FG+=+7%2F5
%28G+%2B+4%29%2FG+=+7%2F5
Multiply both sides by G
%28G+%2B+4%29+=+7G%2F5
Multiply both sides by 5
5%2A%28G+%2B+4%29+=+7G
Simplify
5G+%2B+20+=+7G
Subtract 5G from both sides
20+=+2G
Divide both sides by 2
highlight%2810+=+G%29
Now plug 10 into equation 1 for G
Equation 1: B+=+G+%2B+4
B+=+%2810%29+%2B+4
highlight_green%28B+=+14%29
14 + 10 = 24
There are 24 students in the class