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Okay sy mash members get a whole new section on

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probability or probabilistic reasoning So let's dive in here to

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a deck of cards A standard deck playing cards contains

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four different suits each of which has thirteen cards Assuming

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the deck is shuffled what is the probability of randomly

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drawing two cards of the same suit in a row

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Think of these problems with probability in cards as a

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simpler form of poker Before we draw the first card

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there are a total of four times thirteen or fifty

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two cards in the deck We don't know what the

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same suit is until after we draw the first card

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so it doesn't matter what the first card is right

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The first card makes no contribution to the probability Suppose

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first card we draw is a heart Well it could

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be any suit but we'll use hearts Is an example

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here because we're naturally loving people Hear it Some upright

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we hard hearts Well we took a heart out of

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the deck So now there are only twelve hearts left

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in the deck right One goes away and there's only

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fifty one cards in the whole deck The probability that

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our second card is a heart that is twelve over

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fifty one or twenty four percent not twenty five And

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this is huge is a huge concept You have to

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know this because it'll be on the test We can

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almost promise you this concept but as you take away

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cards your probabilities change All right Because the first card

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could be anything while the probability of randomly drawing two

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cards of the same suit in a row is twenty

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four percent Another way to arrive at same answer it's

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to consider each suit separately For example the probability of

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randomly drawing two hearts in a row is thirteen over

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fifty two times twelve over fifty one Well this probability

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is the same Each of the other three suits we

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don't care which suit the cards are as long as

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it's the same So add up the individual probabilities for

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each suit and you get this mess of a thing

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here thirteen or fit to tone The this thing right

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there four times that quantity because thirteen over fifty two

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equals twelve over fifty one is point two for justice

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before it's kind of like we did a little proof

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there anyway right answer gets d it's twenty four percent 00:02:07.44 --> [endTime] Them's The odds

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