Answer:
7.5%
Step-by-step explanation:
Although they tell us that they are held at the same time, there is no difference between taking out first and then another, because the marbles DO NOT have a replacement.
So the final probability would be:
Total marbles 13 + 33 = 46
The probability of drawing a red would be: 13/46, on the first attempt.
In the second half it would be: 12/45, because we have one less marble and I specify a red one.
Therefore, the final probability is the multiplication of both events, like this:
P = (13/46) * (12/45) = 0.075
In other words, the probability of this happening is 7.5%.
