Probability (Independent events)?

1/3 * 2/5 + 1/3 * 1/2 + 2/5 * 1/2 - 2 * 1/3 * 2/5 * 1/2 = 2/15 + 1/6 + 1/5 - 2/15 = 1/6 + 1/5 = 11/30.