Home › Forums › Decaffeinated Coffee › The Riddle Thread….
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April 28, 2009 10:29 pm at 10:29 pm #1068464kapustaParticipant
I would like to make the people on this thread aware of the many support groups available for detaching yourself from a calculator, and breaking free into an all-human society. 😉
April 28, 2009 10:29 pm at 10:29 pm #1068465aussieboyParticipantdr. pepper: I didnt have a number in mind it was completly random.
Is ICOT right?
April 28, 2009 10:35 pm at 10:35 pm #1068466aussieboyParticipantkapusta: Who uses calculators? I just let someone else use it.
April 28, 2009 10:41 pm at 10:41 pm #1068467April 28, 2009 10:48 pm at 10:48 pm #1068468mroosinsehryMemberdr. pepper, it’s impossibal
April 28, 2009 10:48 pm at 10:48 pm #1068469mroosinsehryMemberwhat door do you always walk into backwards, very rearly frontwards
April 28, 2009 10:55 pm at 10:55 pm #1068470April 28, 2009 10:57 pm at 10:57 pm #1068471I can only tryMembermroosinsehry-
A car door.
April 28, 2009 10:59 pm at 10:59 pm #1068472aussieboyParticipantmroosinsehry: Did you write <stong>rearly frontwards on purpose?
kapusta: lol
April 28, 2009 11:00 pm at 11:00 pm #1068473mroosinsehryMemberkapusta, wrong. (i won’t say the anser i’ll wait till someone guesses!!!!!!)
April 29, 2009 1:01 am at 1:01 am #1068474an open bookParticipantames: no math wizard here but i think if you make up an equation off the top of your head, it might not work out easily, & you might end up with complicated numbers that are hard to deal with.
April 29, 2009 1:36 am at 1:36 am #1068475an open bookParticipantno problem
April 29, 2009 1:41 am at 1:41 am #1068476April 29, 2009 3:05 am at 3:05 am #1068477Dr. PepperParticipantStart with the prime factorization of 1,000,000
= 2 * 2 * 2 * 2 * 2 * 2 * 5 * 5 * 5 * 5 * 5 * 5.
So the two integers must consist of six 2s and six 5s between the two of them.
Any integer that contains a 2 and 5 in it’s prime factorization will end in 0. (2 * 5 = 10 and any integer multiplied by 10 ends in 0.)
=> one integer contains all six 2s and the other one contains all six 5s.
I read this riddle when I didn’t have a calculator nearby (it must have been on shabbos) and the way I calculated (2^6) and (5^6) is by breaking it into squares.
(2^6) = (2^3)^2, we all know that 2^3 = 8 and 8^2 = 64.
(5^6) = (5^3)^2 was a little trickier. 5 * 5 = 25 and 25 * 5 = 125 (5 quarters is 125 cents right?) now 125^2 is what?
Using the trick from the second half of this post http://www.theyeshivaworld.com/coffeeroom/topic/the-riddle-thread/page/8#post-16043
125 * 125 = 100 * ( 12 * 13) + 25 = 15,625.
The two integers are 64 and 15,625 and that is the only solution.
April 29, 2009 3:15 am at 3:15 am #1068478Dr. PepperParticipantames-
Did you ever wonder why all college level math text books are written by professors?
Supposedly they make up questions and give them to their students for homework. The ones with solutions are included in the next edition and the ones without solutions are thrown out or edited by the student for extra credit.
When I was teaching high school the software I used to type up exams had an option to check most of the questions to see if there was a solution. (It could only check the computational ones not the word problems and I never used that feature so I don’t know how well it worked.)
April 29, 2009 4:06 am at 4:06 am #1068479oomisParticipantThe backdoor to a pair of Dr. Dentons?????
April 29, 2009 2:44 pm at 2:44 pm #1068480Dr. PepperParticipantames- I actually heard this from a colleague of mine while I was a teacher and I think he was very serious. Some of the authors list the names of the students who helped review the textbooks.
As far as the software is concerned- I agree that it’s very interesting.
Pretty often when I was creating an exam I started with an answer and went backwards to a question. (For example: X = -3 and 5. Now the question would be “Solve for X: X^2 – 2X = 15.)
The software would ask for ranges for the answers, say from -10 to 10, and design the question accordingly. An advanced option would create a different exam for each student (same questions but different numbers and the correct solutions were randomly placed from A to E for each student). Each test would have a bar code that had to be scanned before the answer sheet was submitted to the Scantron. Of course I couldn’t justify asking the Yeshiva to buy the necessary hardware to combat cheating when it was nonexistent.
I can’t begin to imagine how textbooks were written before PCs. Forget about coming up with problems, just think about the formatting and mathematical notations!
April 30, 2009 1:10 am at 1:10 am #1068481mroosinsehryMemberaob you are right , a car door
April 30, 2009 1:14 am at 1:14 am #1068482an open bookParticipantmroosinsehry: i didn’t have an answer at all. it was icot!
April 30, 2009 1:16 am at 1:16 am #1068483mroosinsehryMemberwhats “icot”?
April 30, 2009 1:23 am at 1:23 am #1068484an open bookParticipantmroosinsehry: a different member by the name of “I Can Only Try” (it’s the initials)
see icot’s answer
http://www.theyeshivaworld.com/coffeeroom/topic/the-riddle-thread/page/21#post-67033
(i’ve never linked before nor referenced a specific post so sorry if it doesn’t work.)
April 30, 2009 1:27 am at 1:27 am #1068485I can only tryMemberoomis1105-
I was thinking along those lines, but decided not to post such an answer.
For the morbidly inclined, “a coffin” would probably be the answer of choice.
an open book-
Thank you.
mroosinsehry-
The young version of an Ibed.
For snack we have Ipeas from an Ipod.
April 30, 2009 1:32 am at 1:32 am #1068486an open bookParticipantwell i’m not sure what happened there with my link, but it does do what it’s supposed to.
icot: no problem. & very cute.
April 30, 2009 4:46 pm at 4:46 pm #1068487Dr. PepperParticipantames- the only hardware missing was the bar code scanner which I can’t imagine was too expensive.
I used a laptop and the yeshiva already had the Scantron sheets and scanner (which could have been hooked up to my computer if I wanted). I would think that they need this more in public schools that prep schools.
May 12, 2009 9:59 am at 9:59 am #1068488Dr. PepperParticipantAnyone want to take a shot at this again?
In the following equation, what Yom Tov does x equal to: 10^x = baomer?
(It was taken from the secular riddle 10^x = cabin.)
May 12, 2009 3:39 pm at 3:39 pm #1068489squeakParticipantLog Baomer = 33
May 12, 2009 10:09 pm at 10:09 pm #1068490ulisisMemberIsn’t that also the integral of 1/baomer dbaomer? Although that would be ln baomer, I guess. Your way is unnatural.
May 12, 2009 11:31 pm at 11:31 pm #1068491JaxMemberulisis: i would like to welcome you back to the cr, seems like you were away long from your profile!
May 13, 2009 2:58 pm at 2:58 pm #1068492Dr. PepperParticipantulisis-
The integral of (1/baomer) dbaomer would be ln |baomer|, (don’t forget those absolute value signs, unless you specify that baomer is strictly positive).
However the integral of 1/(ln(10)*baomer) dbaomer would in fact be Log(BaOmer) since Log (base 10) BaOmer = Ln (Baomer) / LN (10), and stam Logs (no specified base) are base 10.
=> Log (base 10) BaOmer = Log(BaOmer)
May 13, 2009 3:53 pm at 3:53 pm #1068493squeakParticipantDon’t forget
+ C !
May 13, 2009 4:15 pm at 4:15 pm #1068494Dr. PepperParticipantThat’s right, don’t forget the Constant.
May 15, 2009 2:16 pm at 2:16 pm #1068495squeakParticipantHere’s a riddle that someone just sent me, that I liked. Note to Dr. Pepper – please don’t figure it out right away!
You are sitting at a table with 100 pennies on it. You are blindfolded, and told that 90 of the pennies show heads, and the other 10 show tails. You have to split the pennies into two piles, such that the two piles each have the same number of tails. It does not matter if the two piles have the same number of pennies; it only matters that the number of tails must be the same. Assume that you cannot distinguish between heads and tails by touching and feeling the coins (e.g. they are paper cut-out pennies from a kid’s play money). How do you do this?
May 15, 2009 2:32 pm at 2:32 pm #1068496Dr. PepperParticipantCan you turn any of them over?
May 15, 2009 2:36 pm at 2:36 pm #1068497JayMatt19ParticipantWhat if you put them into two piles of 50, with all the coins on their side, like in a roll?
Did I answer correctly or was that a cheat?
May 15, 2009 2:41 pm at 2:41 pm #1068498squeakParticipantDr. P, I don’t see why not. But you shouldn’t be working on this in the first 15 minutes after I posted. I give you a 3 hour handicap, to give someone else the chance.
JayMatt, creative, but cheating. So is taking them off the table. So is rubbing off the heads and tails.
May 15, 2009 2:56 pm at 2:56 pm #1068499I can only tryMembersqueak-
This sounds like a symantic misdirection riddle.
If you put fifty in each pile, each will have the same number of tails (you said have not show.
May 15, 2009 3:07 pm at 3:07 pm #1068500I can only tryMembersqueak-
Never mind – I was wrong.
I lost patience and googled the answer.
Great riddle!
May 15, 2009 3:12 pm at 3:12 pm #1068501moish01Memberhey so did i (thanks for the idea)
really cool one, squeak
May 15, 2009 3:30 pm at 3:30 pm #1068502squeakParticipantWow! There are so many loopholes to close with this riddle! For the record, I meant that the two piles need to SHOW the same number of tails.
May 15, 2009 3:55 pm at 3:55 pm #1068503Dr. PepperParticipantCan you let me know when I can give a shot at it?
I’m waiting very patiently.
Thanks
(Is it just me or is the formatting messed up in this thread?)
May 15, 2009 4:11 pm at 4:11 pm #1068504squeakParticipantI said 3 hours, and it’s been less than 2. I’m just kidding, really. I know that you would probably get the right answer in <2 minutes, so I wanted you to give other people a chance to see the riddle without seeing the answer. But if your engines are revving, go ahead. 😉
BTW, the formatting on this page is messed up since 2 weeks ago. See ICOT’s post above. If a mod would go back and close the expression, all would be back to normal. This happens from time to time.
May 15, 2009 4:22 pm at 4:22 pm #1068505Dr. PepperParticipantMake two piles. One has 90 pennies the other one has 10.
The 90 penny pile has X tails while the 10 penny pile has 10-X tails (and therefore X heads).
Turn over all the pennies in the 10 penny pile and now that pile has 10-X heads and X tails.
Now both piles have X tails. (Although X can be any integer between 0 and 10 inclusive.)
May 15, 2009 6:02 pm at 6:02 pm #1068507I can only tryMemberMy editor pointed out:
Semantic is the word I meant to use.
Symantec is the anti-virus software company.
May 15, 2009 6:36 pm at 6:36 pm #1068508AnonymousInactiveICOT – thanks for pointing that out – its now fixed. Let me know if there is still a problem.
May 15, 2009 6:40 pm at 6:40 pm #1068509I can only tryMemberYW Moderator-25-
You’re welcome.
It’s an issue for Internet Explorer – Firefox displays fine (I don’t have Google Chrome, so I don’t know how it displays there).
It looks fine now on IE.
OK great, thanks! –YW Moderator-25
May 15, 2009 7:22 pm at 7:22 pm #1068510squeakParticipantIs it even necessary for me to say that Dr Pepper has once again given the correct solution.
May 15, 2009 7:26 pm at 7:26 pm #1068511an open bookParticipanti missed this one 🙁 (he really should have that handicap) do you have another one?
May 25, 2009 3:09 am at 3:09 am #1068512yossi z.Memberfor all you gemorah kups out there (and if your not a gemorah kup you can try anyway)
2 people come down a chimney 1 clean the other dirty.
who washes their face?
May 25, 2009 4:46 am at 4:46 am #1068513anonymisssParticipantSanta
~a~
May 25, 2009 5:37 am at 5:37 am #1068514 -
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