Miles has a train collection with 36 engines 72 boxcars and 18 cabooses he wants to arranged the train cars in equal rows with only one type of train car in each row how many can he put in each row.

In order to find how many trains can be put in each row while having only one type of car in each row, you must find the GCF of all the numbers of cars.

First factor all three numbers
36 Engines=      2*2*3*3
72 boxcars =  2*2*2*3*3
18 cabooses=       2*3*3

Since each number contains at least 2*3*3, or 18, each row can be up to 18 train cars in length.
In this case, there will be 1 row of cabooses,
18 ÷18=1
2 rows of engines,
36÷18=2
and 4 rows of boxcars
72÷18=4