Here's my take on this one.......
Call the identifiable boxes
A B C D E F
And I'm assuming that every crate must contain at least one box.
We could select any 4 of the 6 boxes to put in one crate, then select 1 of the 2 remaining boxes to go into a second crate leaving the last box, by default, for the remaining crate....the number of ways to do this is :
4 1 1 6C4 * 2C1 * 1C1 = 30 ways
Or, we could select any 3 of the 6 boxes to put in one crate, then select 2 of the 3 remaining boxes to go into a second crate leaving the last box, by default, for the remaining crate....the number of ways to do this is :
3 2 1 6C3 * 3C2 *1C1 = 60 ways
Or, we could select any 2 of the 6 boxes to put in one crate, then select 2 of the 4 remaining boxes to go into a second crate leaving the last 2 boxes, by default, for the remaining crate....the number of ways to do this is :
2 2 2 6C2 * 4C2 * 2C2 = 90 ways
So....the total number of ways = 30 + 60 + 90 = 180 ways
