You should try this (20+7)+(10+5)=42
C 63 i guesses dude but can be 50 right or wrong
Answer:

Step-by-step explanation:

We start with 12 marbles. So the probability of selecting a red marble is 4/12, or 1/3. Since this marble is not returned, we now have 11 marbles left, so the probability of selecting a second red marble is 3/11. Multiply 1/3 by 3/11, obtaining 1/11.