# The ratio of boys to girls in an art class is 3:5 There are 12 boys in the class. How many girl are in the class?

##### 1 Answer

Nov 30, 2016

#### Explanation:

We can solve this using fractions in ratio form.

Let x be the number of girls.

#"boys" rarr 3/12=5/x larr" girls"#

#color(blue)"cross-multiply"#

#rArr3x=(12xx5)#

#rArr3x=60# To solve for x, divide both sides by 3

#(cancel(3) x)/cancel(3)=60/3#

#rArrx=20# That is, there are 20 girls in the class.

Check :

#12/20=3/5" or " 3:5#