Teacher not available during pandemic, got assignment need support

Question

abe is going to plant 54 oak trees and 27 pine trees. abe would like to plan 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?

Answer 1

You can't do even numbers, as 27 won't divide by 2

Answer is an odd number

27 works

one row of 27 pine trees

and two rows of 27 oak trees

27 is the largest common divisor of both 27 and 54