A nice simple one this week. As ever, please do NOT post your answers, but do say if you think you have solved the puzzle and how long it took. Solution on Monday.
From a full deck of 52 playing cards, how many cards do you need to draw to ensure that you have four of a kind in your hand?
I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for the Kindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.
seams easy, 20 sec.
0.238921961696395381535549104701266481251516152361839 seconds. If you are seriosuly lucky then the first 4 cards drawn could meet the desired criteria. On the other hand,if you are unlucky and the first 39 cards drawn are either say hearts, diamonds or spades, then you need to draw a 40th card
@Dave’s Neighbour: did you miss the bit where Richard said “As ever, please do NOT post your answers”?
I think Dave’s Cross
Richard Wiseman: is it possible to ban certain people by IP address?
Probably not, but it IS possible for you to NOT read the comments until you worked out your answer thereby eliminating the ‘spoiler’ effect.
Dave’s Neighbor, he’s one for you. “Do not look directly at the sun for 10 seconds”
Eh?
Of course it’s possible to ban people by IP adress, blogs do it all the time. Does Dave’s Neighbor do this often? It’s rather rude when one has been expressly asked not to post the answer.
40 seconds
Heh, I see what you did there.
got it, also 20 sec.
Depends. If it’s a random draw it’s another number than when I can pick my own cards
30 seconds
Are the cards face up or face down?
Unless there is a twist – I think I’ve got it.
It would have to be a “nice simple” twist. I don’t see one.
20 seconds
needed a revision, add another 20 seconds
Is this assuming an honest shuffle, break, and deal?
It doesn’t matter if the deck is shuffled or comes as-is from the manufacturer. The answer will still be the same.
Yes,40 seconds.
I didn’t count how long it took me. Under a minute though. You’re right, it wasn’t too tough!
So easy this one. If I’m wrong, shoot me.
Do it yourself. Lazy.
Four of a kind what?
In cards, four of a kind always means four of the same rank. It’s not a trick.
Four of the same suit or number?
Four of the same value card. About 30 seconds.
A fair question, but “four-of-a-kind always means “of the same number” in the context of cards.
“A fair question”, David, but when are Richard’s questions ever fair?
I took it to mean four of the same suit…
Then you took it wrong.
If the deck is face up then the asnwer is 4
So simple I could post the answer and no one would care.
It won’t be obvious to everyone. There is a wrong answer that a good number of people will jump to first.
It would take me ages to draw them like that bloke did a few days ago
Also about 20 sec. It’s interesting that quite a few folks took about 20 sec.
Wait for monday….,its not so a “nice simple one”, i think. Or did you know suddenly what means “four of a kind” ?
Took me 21 seconds. Clearly I’m stupid
I agree with Dave’s Neighbor. The worst case scenario is that you have to wait for the 40th card to ensure 100% success
Do you agree that it’s okay to specifically ignore the instructions regarding posting your answer prematurely? Do you simply not care, or are you cognitively defective, or are you just such a firebrand rebel you can’t help your anti-authoritarian impulses? You and Dave’s Neighbor should start a bad-ass street gang. You could travel town-to-town on souped-up Segways, breaking hearts, scoffing at the law, tearing off mattress tags, and tagging spoilers on Movie Marquis posters with indelible marking pens.
I think he just likes winding you up Mervulon.
You have to admit – he is pretty good at it.
The best way to piss off an attention seeker is to ignore them. Sorry Mervulon, but after your post, I think that Dave/Dave’s neighbour/Anonymous will be back for more on Monday.
That’s okay… just so long as they’re not rolling through my ‘hood on those Segways… we sure don’t need that kind of trouble….
“…. to ensure …” To absolutely guarentee?
I think you will find that the correct spelling is “guarantee”?
Fell into the trap at first, but realised it and figured out the solution! About a minute.
10 seconds, and I should have left it at that.
There’s no point in reading the Friday comments
it took me 25 secs (if my swatch is working properly).
four cards of the same deck require me to draw ___ cards. why is that blank so diffikult for some people?
now if multiple decks are sorted together that would be harder
Why? If it were two packs, the answer would be twice as many, wouldn’t it?
No Martha
No matter how many packs there are the answer is the same
PS Unless we are we playing to Lemmy’s
rules when the answer would be four more
yes m. le twit that does seem to be the case.
a more interesting puzz to me is “how many cards you would have to draw and perhaps discard to guarenty you have four different cards (eg not of same type)”
Actually, with two decks, the answer remains the same. The limiting factor is still how may cards you can draw without making 4 of a kind. Adding another deck doesn’t change that.
Dharmaruci
The answer to your question is the same as that for Richard’s question – different cards though.
It took less time than it would have done to find four of a kind in a pack
The answer we got in half a minute well my incredibly brilliant son got it before I had a chance to finish reading it lol
Less than a minute.
A few seconds.
Yep, just a few seconds. When the puzzle is this easy, I’m sure I’ve gone wrong somewhere.
I can draw cards until doomsday, but none of them will ever mysteriously materialise in my hand, as if by magic, no matter how long I carry on drawing. I fear that I would run out of pencils first. I think it’s a trick question.
I’m not sure if my answer is correct but it took me 32.4 seconds to arrive at it. My thought process was that I always had a one-in-four chance of drawing the same suit of card in a deal (of four cards). I extrapolated this out until I was certtain of having three of a kind in three deals. The last deal might get me the forth four-of-a-kind card on the first card dealt, the second, or the third, but I figured that there would be no doubt that I would have four of a kind by the fourth card. My head hurt by this time, so I had to go lie down.
This is not a puzzle, but just a question…
I see people here make jokes about how easy this puzzle is, but I remember spending a significant amount of time at university doing pigeon hole principle (the basis of this puzzle), and people not getting it and asking many many questions on it during revision sessions. I always found it incredibly easy but apparently it is worthy of being varsity level…
~20 seconds, easy answer, but:
It depends on what you mean by “ensure”; I take it to mean “be certain”.
Are the cards in fact face-down?
Four of WHAT kind? The kind with that particular pattern on the back?
THEN I read some of the comments. Gee, folks, this is becoming just another collection of ad hominem ripostes. Boring.
There just wasn’t enough in this one to get our teeth into. Sorry!
Obviously too straightforward a question for attention seeking pedantics to benefit from. However, as for attention seeking trolls…….
Is it Monday yet?