Part A. First, completely ignoring suit, how many ways are there to pick which 4
ID: 362772 • Letter: P
Question
Part A. First, completely ignoring suit, how many ways are there to pick which 4 of the 5 royal flush card values are in your hand?
Answer 1
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Part B. Alternatively, how many ways there are to pick which 1 of the 5 royal flush card values is not in your hand?
Answer 2
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Part C. Look at your answers to Parts A and B. Notice anything? Do not proceed until you notice something interesting.
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Part D. Okay, so we've dealt with the number of ways to get 4 out of the 5 royal flush card values. But this is an almost-royal-flush we're talking about, so at least four of these cards should be the same suit. How many ways are there to decide which suit an almost-royal-flush will be?
Answer 3
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Part E. Great! Now we have the almost-royal-flush cards' values and suits. So those 4 cards are completely determined, but we still need to decide what the other card should be.
After we selected the first 4 cards, there are 48 cards left in the deck. One of these 48 cards, however, will leave us with an actual royal flush if we pick it. How many ways are there to choose our fifth, and final, card such that we do not end up with a royal flush?
Answer 4
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Part F. The procedure of creating a poker hand that is one card away from being a royal flush consists of 3 steps, all of which must be completed in order to accomplish the task. Use the appropriate rule (product rule or sum rule) to calculate the total number of 5-card poker hands that are one card away from being a royal flush, and your answers from the previous parts.
Answer 5
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Part G. How many 7-card poker hands are one card away from containing a 5-card royal flush? Hint: the first two steps of this procedure are the same as the 5-card problem; it is the last part - picking the card(s) that ruined your royal flush - that needs to be modified.
Answer 6
Explanation / Answer
We have 4 cards of each A, K, Q, J & 10 in the full set of cards.
A. Ignoring the suit we need to pick any 4 cards from A, K, Q, J & 10 of any suit.
No: of ways to do this = 5 * 4 * 4 * 4 * 4 = 1280 ( First pick 4 out of 5 - A, K, Q, J & 10, then pick 1 out of 4 suits for each selected card )
B. Ways to pick 1 Royal Flush Card not in your hand ( ignoring suit ) = 4 ( Pick the remaining card from one of the 4 different suits )
C. The point to note here is that there are innumerable ways to pick 4 out of 5 royal flush cards ignoring suit but only 4 ways of picking the 1 remaining card which is not in your hand. That is once you have got 4 royal flush cards in your hand the probability of getting the 5th card is higher.
D. Ways to decide which suit an almost royal flush would be = 4 ( Since we have only 4 different suits available)
E. Ways to not pick the 5th royal flush card = 47 ( Pick any 1 of the remaining 48 cards except the one which will actually complete a royal flush )
F. Total ways to get an almost royal flush ( considering suit as well ) = 5 * 4 * 47 = 920 ( First pick 4 out of 5 among A, K, Q, J & 10 , then decide which one out of the 4 suits to pick, then pick 1 out of remaining 48 cards except the actual card required to complete royal flush )
G. To get a 5 card royal flush in a 7 card poker hand , Number of ways = 5 * 4 * 47 * 46 * 45 = ( Same Logic as F part except that we need to pick 2 more normal cards from the remaining set of cards excluding the actual card to complete the royal flush )