A box contains 6 red marbles and 9 blue marbles. What is the probability of randomly selecting 2 red marbles successively without replacement?

Answer 1

The probability of selecting the first red marble is 6/15 because there are 6 red marbles out of a total of 15 marbles.
After removing the first red marble, there are 5 red marbles left out of 14 total marbles.
Therefore, the probability of selecting the second red marble is 5/14.
Since the events are successive, we can multiply the probabilities: P(selecting 2 red marbles successively) = (6/15)*(5/14) = 30/210 = 1/7.
So, the probability of randomly selecting 2 red marbles successively without replacement is 1/7. Answer: \boxed{\frac{1}{7}}