Your question is Probability With Two Buckets. 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).
If you have 50 red balls and 50 blue balls with two buckets and a child is choosing one of the buckets at random, how would you place the balls to maximize the probability the child chooses a red ball?