Alternate approach:
Bunuel
Two cards are drawn at random from a pack of 52 cards without replacement. What is the probability that one is a club and other is an ace?
A. 1/52
B. 1/26
C. 1/13
D. 4/13
E. 7/13
AND means MULTIPLY.
OR means ADD.
Case 1: P(ace of spades, diamonds or hearts AND any type of clubs)P(first card is an ace of spades, diamonds or hearts) = 3/52 (Of the 52 cards, 3 are the ace of spades, diamonds or hearts)
P(second card is clubs) = 13/51 (Of the 51 remaining cards, 13 are clubs)
Since Case 1 requires the first card AND the second card, we multiply:
3/52 * 13/51 = 1/4 * 1/17
Since the two cards can also be picked in reverse order, we multiply by 2:
1/4 * 1/17 * 2 =
1/2 * 1/17Case 2: P(ace of clubs AND any other type of clubs)P(first card is ace of clubs) = 1/52 (Of the 52 cards, 1 is the ace of clubs)
P(second card is clubs) = 12/51 (Of the 51 remaining cards, 12 are clubs)
Since Case 2 requires the first card AND the second card, we multiply:
1/52 * 12/51 = 1/13 * 1/17
Since the two cards can also be picked in reverse order, we multiply by 2:
1/13 * 1/17 * 2 =
2/13 * 1/17Since a favorable outcome will be yielded by Case 1 OR Case 2, we add the results in blue:
(1/2 * 1/17) + (2/13 +1/17) = (1/17)(1/2 + 2/13) = (1/17)(17/26) = 1/26