If this is an option, it should be Similar Triangles.
Separating the balloons into five equal groups
<span>⊙⊙⊙ ___ ⊙⊙⊙ ___ ⊙⊙⊙ ___ ⊙⊙⊙ ___ ⊙⊙⊙ </span>
<span>each group (fifth) has three balloons ___ four-fifths is twelve</span>
12/80
=15 percent
There are 80 apples in the crate
Do 12 divided by 15 then multiply by 100 = 80