Question #5d8b7

Mar 28, 2017

19 boys and 13 girls

Explanation:

Rewrite the word problem as an equation:

$b + g = 32$

$b + 2 g = 45$

Use elimination. Subtract the top equation from the bottom equation:

$g = 13$

Now plug into one of the equations. I will plug into the first one:

$b + 13 = 32$

$b = 19$

Mar 28, 2017

$13$ girls in the class.

Explanation:

It is possible to answer the question without using any equations or algebra at all.

The number of student is $32$.

However, with the number of girls doubled, the total is $45$.

Therefore the difference in the two totals is the number of girls, because the number of girls was added on again.

$45 - 32 = 13$ girls in the class.

Check:

$13$ girls + $19$ boys = $32$

$13 + 13$ girls + $19$ boys

$= 26 + 19 = 45$