Probability

To find the probability of drawing two red balls without replacement, we use the combination method:

1. Total balls: 4 red + 6 blue = 10 balls.
2. Calculate the number of ways to choose 2 red balls:
3. Calculate the total ways to choose 2 balls from 10:
4. Compute the probability:
5. Alternative method (sequential probability):
6. Match with options: .

Thus, the correct answer is: