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

Answer:

#20" girls"#

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#