There is 350 boys the the ratio is 2 (or 2 1/2) boys for every 1 girl
The shape resulted is a square
x=3.555555555
10x=35.55555555
subtract the first equation from the second
10x=35.55555555
- x=3.555555555
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9x = 32
x = 32/9 or 3 5/9