Abe is going to plant 54 oak trees and 27 pine trees. Abe would like to plant the trees in rows that all have the same number of trees and are made up of only one type of tree. What is the greatest number of trees Abe can have in each row?

Abe is going to plant 54 oak trees and 27 pine trees
 greatest number of trees Abe can have in each row =?
54 = 2 x 27
27 = 1 x 27
Now 27 is the common in both numbers and also is the greatest number
So, there are 2 rows of oak trees and 1 row of pine trees and all the rows have 27 number of trees.