You are planting 12 oak trees 15 maple trees and 9 spruce trees in a park you want to plant equal group of trees without mixing types of trees what is the greatest number of trees planted per group?

The largest common divisor of 12, 15 and 9 is 3, so 3 would be the largest number of trees possible in each group, if all groups are to have the same number of trees. This would give: * 5 groups of Maples,

* 4 groups of Oaks, and

* 3 groups of Spruce. A total of 12 groups of trees.