Paul has a collection of 36 marbles. He separated the marbles into 3 equal groups to share with his friends, but he decided to keep 2/3 of the marbles for himself. How many marbles will Paul keep?
36 divided by 3 equals 12
1/3 is equal to 12
2/3 is equal to 24
3/3 or 1 is equal to 36
Therefore, the answer would be 24.