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Work Shown
B = number of boys
G = number of girls
Since the ratio of boys to girls is 3:4, this means
B = 3x
G = 4x
where x is any positive integer. The ratio 3x:4x reduces to 3:4 when we divide both parts by x.
Since there are 48 girls, we know that G = 48. We also know G = 4x. Equate the two items and solve.
4x = 48
x = 48/4
x = 12
This means
B = 3x
B = 3*12
B = 36
So we have 36 boys and a total of B+G = 36+48 = 84 students.
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Here's another way to figure out how many boys there are in the class.
(number of boys)/(number of girls) = 3/4
B/G = 3/4
B/48 = 3/4 .... plug in G = 48
B*4 = 48*3 ... cross multiply
4B = 144
B = 144/4 .... divide both sides by 4
B = 36
