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What is the probability that a 5-card straight flush will be drawn (a straight flush is 5 cards in a row, all cards the same suit) if the first two cards drawn are the 2 of spades and the 6 of spades

User Keibosh
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2 Answers

3 votes

Final answer:

The probability of drawing a 5-card straight flush after having the 2 and 6 of spades is 1/58,800, considering the sequences that can complete the hand.

Step-by-step explanation:

To calculate the probability of drawing a 5-card straight flush from a standard deck of 52 cards after having drawn the 2 of spades and the 6 of spades without replacement, we need to consider the cards that can complete this hand. For a straight flush with these two cards, the only possible sequences include A-2-3-4-5 or 2-3-4-5-6 or 3-4-5-6-7. Since the 2 is already included, the three sequences reduce to A-3-4-5, 3-4-5, and 4-5-6-7.

The three remaining cards need to be the 3, 4, and 5 of spades or the 4, 5, and 7 of spades. There are initially 50 cards left in the deck after the first two have been drawn. The probability of successively drawing the 3, 4, and 5 of spades would be (1/50) * (1/49) * (1/48), and similarly, the probability to draw 4, 5, and 7 of spades would be (1/50) * (1/49) * (1/48). We add these probabilities since either sequence will result in a straight flush.

As a result, the combined probability is 2 * (1/50) * (1/49) * (1/48), because we have two distinct sequences that can complete the straight flush. Simplifying, we get 1/58,800, which is a very low probability.

User Bryan Miller
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4 votes

Answer:


\mathbf{(1)/(19600)}

Step-by-step explanation:

From the information given:

For 5 cards to be drawn where the first two are 2 spades and 6th of the spade.

Then the cards should be: 2,3,4,5,6 of spade.

Since 2 and 6 are already drawn.

Then;

the 3rd card maybe 3, 4, or 5 of the spade.

Thus, the probability that it is the third card is: 3/50

The probability is the 4th card 2/49 ; &

The probability that it is the fifth card is 1/48

Thus, the probability that a 5-card straight flush is drawn is:


P(5) = 1 * 1* (3)/(50)* (2)/(49) * (1)/(48)


P(5) = (1)/(19,600)

User Siddarth
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