Your question is Marble Bag Logic. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
You have 3 bags of marbles: one full of green, one full of red, and one mixed. All are labeled incorrectly. How many marbles must you remove to correctly identify the contents of each bag?