An urn contains 3 red and 4 green marbles. If three marbles are picked at random, what is the probability that two are green and one is red?
Correct Answer: 18/35
Explanation:
Number of ways to select 3 marbles out of 7 marbles = n(s) = 7C3 = 35
Probability that 2 are green and 1 is red = n(E) = 4C2 x 3C1 = 18
∴ Required probability = 18/35
