Final answer:
The probability of selecting either a red or yellow marble from the bag is 9/13, which is approximately 3/5.
Step-by-step explanation:
The subject of this question is probability, a topic within mathematics, and is suitable for a high school level of understanding. In probability, to find the chance of selecting either a red or yellow marble from the bag, one would add the individual probabilities together since these are non-overlapping events (meaning a marble cannot be both red and yellow).
Given there are 3 red, 4 blue, and 6 yellow marbles in the bag, the total number of marbles is 3 + 4 + 6 = 13. The probability of selecting either a red or yellow is the sum of the individual probabilities: P(red or yellow) = P(red) + P(yellow) = (3/13) + (6/13) = 9/13.
The correct answer to the student's question is not listed among the provided options. However, based on the calculations, the probability of selecting a red or yellow marble is 9/13, which can be reduced to approximately 3/5 if we round to the nearest whole number fraction available among the options.