Answer:
1. 4/11 2. 2/10 or 1/5
Step-by-step explanation:
The first thing you need to do is find the total number of marble and then break it into their probabilities. 4+2+5= 11
Red: 4/11, Yellow: 2/11 and Blue: 5/11
So for 1. you just need the probability of pulling a red marble with we already figured out, 4/11.
For the second part you're looking for the probability of pulling a yellow marble after a red was pulled and not replaced. When we take one out and don't replace it the only thing that changes is the total and the number for that color so, the probabilities change to: Red: 3/10, Yellow: 2/10 and Blue: 5/10.
So now you have the probability of pulling a yellow if a red was pulled first without being replaced.