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"Simple" Maths Problems II
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Luke Send message Joined: 31 Dec 06 Posts: 2546 Credit: 817,560 RAC: 0 |
A new thread, and perhaps new SETIzens?! A Big Hello to everyone who participated in my previous thread & and anybody new that will participate in this thread! For all participants, new or old: 1. Welcome to the Simple Maths Problem thread! 2. Answer my question correctly, and earn 1 or 1/2 a point for the stats table. 3. Only the first correct answer is given points. 4. Solutions would be desired (although not compulsory) for all questions. 5. 'Easy' questions (worth 1/2 a point) should be completed without a calculator. 6. You may use any method (unless specified) to answer 'Hard' Questions (worth 1 point) 7. This thread will be more 'casual' than the previous thread. 8. Have fun! So, here we go, lets start it off easy... Question 1 ( 1/2 point) : Fill in the gaps: 1,2,4,3,6,12,10,20,40,__,__,__ Luke. - Luke. |
Sarge Send message Joined: 25 Aug 99 Posts: 12273 Credit: 8,569,109 RAC: 79 |
30, 60, 120 Capitalize on this good fortune, one word can bring you round ... changes. |
Luke Send message Joined: 31 Dec 06 Posts: 2546 Credit: 817,560 RAC: 0 |
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Fred W Send message Joined: 13 Jun 99 Posts: 2524 Credit: 11,954,210 RAC: 0 |
Q1: 37, 74, 148 But the derivation does seem somewhat obtuse. F. |
Luke Send message Joined: 31 Dec 06 Posts: 2546 Credit: 817,560 RAC: 0 |
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The Gas Giant Send message Joined: 22 Nov 01 Posts: 1904 Credit: 2,646,654 RAC: 0 |
36, 72, 144 |
Luke Send message Joined: 31 Dec 06 Posts: 2546 Credit: 817,560 RAC: 0 |
Well Done The Gas Giant! Question 1 Answer: 36, 72, 144 Standings: 1. The Gas Giant - 1/2 Point 2. TBD... Another one: Question 2 (1 Point): Of three men one man always tells the truth, one always tells lies, and one answers yes or no randomly. Each man knows which man is who. You may ask three yes/no question to determine who is who. If you ask the same question to more than one person you must count it as question used for each person whom you ask. What three questions should you ask? Luke. - Luke. |
William Rothamel Send message Joined: 25 Oct 06 Posts: 3756 Credit: 1,999,735 RAC: 4 |
Just dropped in to say hello--I am spending my Math hours now on preparing to teach my class on Probability and Statistics at Devry University in Nashville.. Hint on this problem. You can permute 3 things 3 x 2 = 6 ways ( 3 guys and truth/liar) Make a truth table as you would in computer logic design The solution is not obvious and would require a lot of time. Good one for others Back to sleep now |
W-K 666 Send message Joined: 18 May 99 Posts: 19065 Credit: 40,757,560 RAC: 67 |
Well Done The Gas Giant! I have to ask the obvious, Why? I agree with Sarge. Standings: |
Beethoven Send message Joined: 19 Jun 06 Posts: 15274 Credit: 8,546 RAC: 0 |
I'm a mathematical total idiot, so here's how I handled Problem 2: 1. Identify the type of problem: this is a logical problem 2. Identify the scale of difficulty: all the problems on this "Simple" thread are very hard 3. Search Wiki for "The Hardest Logic Problem in the World". I wouldn't dream of trying to solve this one, but at least I now know how you guys can go about solving it. :]] Good Luck!!! |
Luke Send message Joined: 31 Dec 06 Posts: 2546 Credit: 817,560 RAC: 0 |
Well Done The Gas Giant! Here's the answer: (doubling every three) 1, 2, 4, (minus the first number in the series - 1) 3, 6, 12, (minus the second number in the series - 2) 10, 20, 40, (minus the third number in the series - 4) 36, 72, 144. Luke. - Luke. |
Luke Send message Joined: 31 Dec 06 Posts: 2546 Credit: 817,560 RAC: 0 |
Do we have any answers for Question 2? Question 2 (1 Point): Of three men one man always tells the truth, one always tells lies, and one answers yes or no randomly. Each man knows which man is who. You may ask three yes/no question to determine who is who. If you ask the same question to more than one person you must count it as question used for each person whom you ask. What three questions should you ask? Luke. - Luke. |
Fred W Send message Joined: 13 Jun 99 Posts: 2524 Credit: 11,954,210 RAC: 0 |
Do we have any answers for Question 2? Patience,Luke. That is at least a 3-day tariff question and deserves more than 1 point ;). I am coming to the conclusion that there are not 3 generic questions that will work under all circumstances. In other words, the 3rd question will differ depending on the answer to the second so we would have to come up with the alternative versions of the 3rd question to fit the different situations; i.e. more than 3 questions to be formulated. Or have I found the wrong tree to bark up? F. |
Luke Send message Joined: 31 Dec 06 Posts: 2546 Credit: 817,560 RAC: 0 |
Do we have any answers for Question 2? Would you like the first Question Answer? ;-) Luke. EDIT : Hint, label each of the three men; A, B, & C. - Luke. |
Fred W Send message Joined: 13 Jun 99 Posts: 2524 Credit: 11,954,210 RAC: 0 |
Do we have any answers for Question 2? Woof, woof. It's the right tree ;) F. |
Fred W Send message Joined: 13 Jun 99 Posts: 2524 Credit: 11,954,210 RAC: 0 |
Well Done The Gas Giant! Q2: First of all name the men Alf, Bert and Cecil. Ask Alf q1: "Does the name of the man who can give random answers (let's call him 'R') have one more letter than the that of the man who always tells lies ('L')?" If Alf answers "Yes" and he is telling the truth then he, himself can't be R, so to complete the set we will call him 'T', R must be Cecil and L must be Bert. If Alf answers "Yes" and is lying then he could be L or R. His answer tells us that, if he is 'L' then Bert can't be 'R' and that if Alf is 'R' then Bert can't be 'R'. All of the above indicate that Bert can't be 'R' If Alf's answer to q1 is "No" then all of the above applies but with Bert / Cecil reversed so Cecil can't be 'R'. Ask whichever has been identified as NOT being 'R' in the above (Bert / Cecil) q2: "Are you the man who can tell the truth or lie?" If he answers "Yes" then he is lying and he must be 'L' since we already know that he can't be 'R'. In this case ask the same man q3: "Does Cecil / Bert {the third man} always tell the truth?". If he says "Yes" then the third man is capable of lying and must be 'R' so Alf must be 'T'; otherwise If the third man always tells the truth ('T') and Alf is 'R'. If the answer to q2 were "No" we know this is the truth and he must be 'T'. In this case ask the same man q3: "Does Does Cecil / Bert {the third man} always lie?". If he says yes then the third man is 'L' and Alf is 'R'; otherwise the third man is 'R' and Alf is 'L'. So the second question is the same but asked of different men; the third question has 2 variants of which only one will be used. But I have had to formulate more than 3 questions. Woof woof? F. |
Luke Send message Joined: 31 Dec 06 Posts: 2546 Credit: 817,560 RAC: 0 |
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jason_gee Send message Joined: 24 Nov 06 Posts: 7489 Credit: 91,093,184 RAC: 0 |
... 4292 "Living by the wisdom of computer science doesn't sound so bad after all. And unlike most advice, it's backed up by proofs." -- Algorithms to live by: The computer science of human decisions. |
W-K 666 Send message Joined: 18 May 99 Posts: 19065 Credit: 40,757,560 RAC: 67 |
Well Done Fred! That was an exceptionally hard problem! (8+144-12x3)x(18x2-3+4)=4292 Jason beat me by seconds. Still think Q1 is very dubious, if it had asked for the next series it would have been un-ambiguous. |
Luke Send message Joined: 31 Dec 06 Posts: 2546 Credit: 817,560 RAC: 0 |
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