Geometry

Question Analysis
This question involves conditional probability with multiple sequential events without replacement.
The main focus is on adjusting the sample space and the number of favorable outcomes after the first two events (drawing two red marbles) to find the probability of the third event (drawing a blue marble).

Key Concept Explanation
For multiple sequential non - replacement events, each prior event changes the sample space and the number of favorable outcomes for the subsequent events.
Conditional probability helps us calculate the probability of an event based on the events that have already occurred.

Step-by-Step Solution
When the first two marbles drawn are red, the number of red marbles left is , the number of green marbles remains 4, and the number of blue marbles remains 5.
The total number of marbles left in the bag is

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