MagnusRM

You have 6 boxes. In each box is a number. One box has 1 inside, another has 2, and so on up to 6. On the outside of each box are also numbers, from 1 to 6. An outside number might or might not match its corresponding inside number.

Your task is to determine whether or not all the outside numbers match the inside numbers. To investigate the situation you may create two groups of boxes and give those two groups to a smart dog.

The dog can smell the inside number of each box and can add up the "internal" sum of each group and compare with that of the other group. The dog will point to the group with the greatest sum. If they are equal he will just shake his head.

You do not have to include all the boxes when you give the dog two groups. You can only ask the dog two times to help you like this. How can you accomplish your task?