In a box carrying one dozen of oranges, one third have become bad. If 3 oranges are taken out from the box at random, what is the probability that at least one oranges out of the three oranges picked up is good?
Correct Answer: 54/55
Explanation:
n(S) = 12C3 = (12 x 11 x 10) / (3 x 2) = 2 x 11 x 10 = 220 No. of selecting of 3 oranges out of the total 12 orange = 4C3 = 4
∴ n(E) = No. of desired selection of oranges = 220 - 4 = 216 ∴ P(E) = n(E) / n(S) = 216 / 220 = 54/55
