Question

There are 40 children on a bus, there are 12 more boys than girls, how many girls are there on the bus?

Answer 1

b = boys

g = girls


There are 40 children on a bus mean:

b + g = 40

There are 12 more boys than girls mean:

b = g + 12


b + g = 40

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Remark:

You know:

b = g + 12

Replace this value in equation:

b + g = 40
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g + 12 + g = 40

2 g + 12 = 40

Subtract 12 to both sides
2 g + 12 - 12 = 40 - 12

2 g = 28

Divide both sides by 2


g = 28 / 2 = 14


14 girls