A jar has 6 marbles, 1 blue, 1 white, 1 green, 1 yellow, 1 red, 1 black. If 5 marbles are removed at random, what is the probability that the green marble was removed?
The desired probability is
The probability that the green marble is removed in first instant is
Hence, the probability that green marble is there among remaining
This is equivalent to taking
Hence desired probability is