Current Events > If there's a 1/7 chance you draw a specific card, and you draw 7 cards

(+) Yeah! (+)

There's a 100% chance you draw that specific card

Prove me wrong
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this is only true if the total number of cards is 7
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Really makes you think
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averagejoel posted...

this is only true if the total number of cards is 7

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averagejoel posted...

this is only true if the total number of cards is 7

1/7 means 1/7
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1/7 also means 4/28, or 9/63

If you have 63 cards and 9 are blue, you do NOT have a 100% chance of having a blue card after drawing seven.
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makes sense to me
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This is false. The card is actually inside of the bottle, therefore you cant draw it
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Only if those 7 cards are identical.
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you have a 50% of drawing the card
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The card is the planet and the chance is the room outside
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prettyprincess posted...

you have a 50% of drawing the card

that's true

then you multiple 0.50 by 1/7
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If the cards are replaced each time, you have a 66% chance of drawing the specific card in 7 chances.
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Did you guys not do basic math? It depends on how many cards there are.

Let's say there's 70 cards total, and 10 of them are Aces. You want to draw an ace.

On the first draw, you have a 10/70 chance, or 1/7 chance, of drawing it.
If you didn't get it, then on the next draw you have a 10/69 chance of getting an Ace.
If you still didn't, you now have a 10/68 chance of getting an Ace.
Etc.

So if there's 70 cards and 10 are Aces, the chance of drawing an Ace is 7 pulls is definitely not 100%.

The amount of cards is irrelevant to the answer.
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sumuthergamer posted...

So if there's 70 cards and 10 are Aces, the chance of drawing an Ace is 7 pulls is definitely not 100%.

ding ding ding
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The Admiral posted...

The amount of cards is irrelevant to the answer.

Only if you're a moron.

sumuthergamer posted...

The Admiral posted...

The amount of cards is irrelevant to the answer.

Only if you're a moron.

Or if you understand how probability works.
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CE always falls for this topic.
Think there was one just last week.
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sumuthergamer posted...

So if there's 70 cards and 10 are Aces, the chance of drawing an Ace is 7 pulls is definitely not 100%.

specifically, it's 67.78%
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Darkman124 posted...

sumuthergamer posted...

So if there's 70 cards and 10 are Aces, the chance of drawing an Ace is 7 pulls is definitely not 100%.

specifically, it's 67.78%

Yes, if the cards are not replaced.

However, the question implies the cards are replaced, otherwise the odds are not 1/7 on any draw except the first. If they are replaced, the probability is 66%. And this doesn't change whether there are 7 cards or 7,000 cards in the deck.
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mhm, then you're just doing P(not X) ^ n
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This is easily proven false by looking at pokemon encounter rates.

Beldum has a 1/10 chance of appearing in the grass of Mt. Holukani in Gen 7. But it took me significantly more than 10 encounters to find one. (I didn't count, but it was over 30.)

Ergo, you cannot simply multiply the rate by the trials.

Also, Admiral is correct that the number of cards doesn't matter. (Similarly, the number of pokemon doesn't matter; it's infinite.) We can still draw conclusions based entirely upon the rate and number of trials, assuming (as he said) that we draw from the same pool of cards each time.
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Alkaloid posted...

This is easily proven false by looking at pokemon encounter rates.

Beldum has a 1/10 chance of appearing in the grass of Mt. Holukani in Gen 7. But it took me significantly more than 10 encounters to find one. (I didn't count, but it was over 30.)

Ergo, you cannot simply multiply the rate by the trials.

Also, Admiral is correct that the number of cards doesn't matter. (Similarly, the number of pokemon doesn't matter; it's infinite.) We can still draw conclusions based entirely upon the rate and number of trials, assuming (as he said) that we draw from the same pool of cards each time.

the number does matter though - op is correct if the number of cards is 7
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prettyprincess posted...

you have a 50% of drawing the card

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averagejoel posted...

the number does matter though - op is correct if the number of cards is 7

AND if you're not replacing them
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But you're making a bad assumption. If the number is not specified, you must assume it's unknown. He could just as easily have 52 cards, or an infinite number of cards.

All that matters is that any given draw has a ~14% chance of being what you want.
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Darkman124 posted...

averagejoel posted...

the number does matter though - op is correct if the number of cards is 7

AND if you're not replacing them

But what if the card is a 7? That changes everything.
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Since the topic does not state any details. The simple answer is ~66%.

The chance to not draw the card is 6/7.

6/7 ^ 7 = ~0.34. Which is 34% chance to not draw the card. Which means 1 - 0.34 = 0.66 which is a 66% chance to draw the card at least once.
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one out of every seven cards

if you draw seven cards, one will be the one you want

that is how probability works
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Darkman124 posted...

averagejoel posted...

the number does matter though - op is correct if the number of cards is 7

AND if you're not replacing them

If you're not replacing them then the title is worded poorly, because you don't have a 1/7 chance on the 7 draws.
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