Three cards are chosen at random from a standard 52-card deck. What is the probability that they are not all the same color?

1 answer

3 card combinations ... 52C3

black 3 card combinations ... 26C3

red 3 card combinations ... 26C3

probability not same color = 1 - (probability of same color) = 1 - [(2 * 26C3) / 52C3]