Hello There!
This is a multiple step problem, to solve this you have to multiply and divide.
Steps
1. Divide 12 by 3
2. You should get 4, to check you're answer do 34 which equals 12
3. To find how many hexagons there are, you have to do 45 which equals 20
So, on Adriana's soccer ball if there are 12 pentagons, there should be 20 hexagons.
Hope This Helps :)