Answer: The probability of selecting a six as the first card is 4/52, since there are four sixes in a standard deck of 52 playing cards.
After the first card is drawn, there are 51 cards remaining in the deck, so the probability of selecting a king as the second card is 4/51, since there are four kings left in the deck.
Since we want to find the probability of selecting a six and then a king, we need to multiply the probabilities of these two events:
(4/52) x (4/51) = 16/2652 = 4/663
Therefore, the probability of selecting a six and then selecting a king is 4/663.