Correct
Explanation
Taking out 3 of each color will ensure that he has 1 of each color. Thus, he needs to take out 9 marbles, in all.
Solve this puzzle
1 is 3, 3 is 5, 5 is 4, 4 is perfect. Why?
5 = 4 4 has 4 letters 3 = 4 4 is a prime number