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3 years ago

Two-thirds of a class are boys. If there are 12 boys, then how many girls are in the class?

Mathematics

1 answer:

son4ous [18]3 years ago

6 0

Step-by-step explanation:

so 2/3 OF the class are boys...

***REMEMBER IN MATHEMATICS, ^OF^ IS USED TO SAY MULTPLICATION***

so 2/3 OF class(x) are boys and there are 12 boys...

so 2/3 * x = 12

12 / (2/3) = x

to solve use the Keep, Change, Flip method

Keep 12, change / to multiplication, flip 2/3 to 3/2

it becomes 12 * 3/2 and to solve easier 12 is same thing as 12/1

12/1 * 3/2

Multiply across (numerator by numerator and denominator by denominator)

(12*3) / (1*2) = 36 / 2

Simplify

So the class has 18 students, and 2/3 of boys (12 of the students)

we can solve for how many girls are in the class

Depending on how your teacher wants to see the work:

either 18 - 12 = 6

or 1/3 * 18 which we rewrite as 1/3 * 18/1 = (1*18)/(3*1) which is 18/3... simplified it is 6

There are 6 girls in the class.

Hope this helps! :)

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