Solution re 5 concentric, superposed discs

[suckmymuscle]

Yeah I don't think suckmymuscle even understands that these sort of problems are usually distributed in a setting where you have access to a computer...

  This is not a problem that can be solved with computer algorithms if you don't start with the right axioms for the solution. Postulating that it is a matter of simple alignment would be correct if they were all in the same position at the start of the movement and the test designer asked you when the dots would be aligned again for the first time. But the questions makes it clear that the dots were not aligned. Hence, your answer is incorrect. Do you really think it took over a year for the dots to be aligned for the first time? Honest question.

SUCKMYMUSCLE

[Shockwave]

 Guys, your solution would be corect - I made the same mistake - if the red dots in the disks were aligned at first, but they aren't. The question is not when the red dots will be aligned again after they start spinning at their own velocities and directions, but when they will be aligned for the first time. Your solution is incorrect.

SUCKMYMUSCLE

It doesnt matter if theyre not aligned...
7 minutes is 7 minute.. 9 minutes is 9 minutes.
Disc D is aligned when it is 7 minutes from the point it STARTED AT. Its right there in the prompt.
Your answer of 9 minutes means disc D would have moved...... wait for it..... 9 minutes from its starting point. Doesnt matter where it started. Which way it spins, etc,  
Why cant you grasp that?

[Lumberjack88]

  Cephiseus, let me ask you a question: do you really think it took more than a month for the red dots to be aligned for the first time? LMAO!

SUCKMYMUSCLE

I've constructed equations for each disk, as you can see here:


So where is my mistake? These equations in the beginning are based on the premises that i posted, and that you agree with, at least I think so. What you don't agree with is the solution. But where exactly am I wrong, in your opinion?

It's basically a simulation.. i let these disks spin mathematically... the computer has not used logic or reason... it's pure brute force. Trial and error... looking out for the correct time... nothing more. The only thing that can be wrong.. are my functions of motion for each disk... and unless you can disprove these functions... my solution is correct.

Btw, it is indeed possible that this system of disks needs almost a year to get to the aligned position... because there are 5 disks involved... that turn with different velocities... and those are only dots that have to be aligned, not big surfaces. So the probability of the alignment is not very big.

[chaos]

 

[cephissus]

LOL

I'm certain suckmymuscle isn't even trolling... he genuinely believes 9 minutes is the correct answer.

A person enjoys making dishonest posts (ie trolling) only when, in doing so, they can get others to say something stupid.  After he has accomplished this, the troll always has to go show his friends and laugh, or eventually expose his victim in front of a crowd.  The end goal is always to make someone else look stupid -- either to the troll, his friends, or even to the victim himself.  People often take this approach when they don't know the answer, but are sure that the person they are trolling doesn't either.  Otherwise, if they did know the answer, they would usually just come straight out and own them.

If suckmymuscle didn't believe his own answer (ie was trolling), he wouldn't be getting any enjoyment out of this since we are doing nothing but shoving the correct answer in his face over and over again, making him look more pathetic with every passing post.  He would either know that our answer is correct, or he wouldn't be sure.  And if he wasn't sure, he wouldn't troll, since there's so much evidence in our favor that even a person of modest intelligence thinks, at this point, that we're right.

Maybe his resolve is weakening by now, and he's just clinging to his false answer in hopes that he can scare us off by pure bluster, and somehow everyone will forget this ever happened.  Unfortunately, I have a feeling he won't, they won't and...

he won't recover.

[Lumberjack88]

After a certain time, all the red dots were aligned, disc A being in the same position that it was 2 minutes after the discs started to spin, disc B being in the same position that it was 3 minutes after the discs started to spin, disc C being in the same position that it was 4 minutes after the discs started to spin, disc D being in the same position that it was 7 minutes after the discs started to spin, and disc E being the same position that it was 9 minutes after the discs started to spin

After a certain time, all the red dots were aligned.

Conclusion: There was an alignment.

Disc A being in the same position that it was 2 minutes after the discs started to spin.

Conclusion: So when the aligned position happened, Disk A was in the same position that it was 2 minutes after start. THAT'S THE ONLY POINT, WHERE DISK A CAN ALIGN, LIES!

Here's the most important conclusion:

NOW WE KNOW THE ALIGNMENT POINTS!

Disk A = 2 min after start

Disk B = 3 min after start

Disk C = 4 min after start

Disk D = 7 min after start

Disk E = 9 min after start

Another conclusion: These discs can only reach their alignment position after they completed a full 360° turn. There is no way in hell that Disk B can reach it's alignment position, which it reaches after 3 min of spinning, again in under 6 min, because the angular velocity of Disk B is 360/13 [°/min] ~27.7° per minute...

But the questions makes it clear that the dots were not aligned. Hence, your answer is incorrect. Do you really think it took over a year for the dots to be aligned for the first time

They were not in full alignment, meaning not all the dots were in line, nevertheless each disk reached, at their corresponding times, their individual alignment position, the only position, where alignment with the other disks is possible. And these times were measured AFTER the mechanism started to move.. these disks just surpassed their alignment points after 2,3,4,5,7,9 minutes, doesn't mean that every point was in line then.

This is not a problem that can be solved with computer algorithms if you don't start with the right axioms for the solution.

It can be solved by algorithms... so many mathematical theses have been proven by numerical methods... google calculates much harder linear algebraic problems with its page ranking system almost instantly...etc.

Why do you think that a computer cannot simulate 5 disks, with velocities and fixed alignment points?


You constantly emphasize the FIRST alignment that happened, and that cephissus and I did not calculate the FIRST alignment... so would you agree that I calculated the time, the second alignment happened, correctly? Because the third alignment, if we can trust my computer's and cephissus computer's calculations, happened 1'153'896 minutes after start... that just shows how small the probability is of this event happening frequently e.g. each day or even month.

[Shockwave]

The 2 above posters are FAR more intelligent than I...
And even I can figure out that SMM answer is blatantly impossible.
SMM is not the kind of guy to admit hes wrong until the last minutes. Im not sure if he ever will, but if he does, itll be at the last possible minute just to try and save face. 

[suckmymuscle]

It doesnt matter if theyre not aligned...
7 minutes is 7 minute.. 9 minutes is 9 minutes.
Disc D is aligned when it is 7 minutes from the point it STARTED AT. Its right there in the prompt.
Your answer of 9 minutes means disc D would have moved...... wait for it..... 9 minutes from its starting point. Doesnt matter where it started. Which way it spins, etc,  
Why cant you grasp that?

  Shockwave, I like you because of the truce thread, so I am going to be polite to you.

  What you fail to grasp is that this is true only for the first spin. The disk will be at the point where it aligns with disk E again two minutes after it has completed a full spin. Why? Because the positions where they align have tnothing to do with the time each disk takes to spin as all dots are not aligned at the beggining. I don't know how I can make this any simpler.

SUCKMYMUSCLE

[suckmymuscle]

  LOl, at the two dumbasses who think it took over a year for the dots to align for the first time.

  Your answer would be correct if the dots were aligned at first and the test maker asked you when they aligned again for the first time. But the dots were not aligned. The fact that the speed is constant and that they give you the time it takes for each disk to spin would allow you to calculate the moment when the disks aligned if the dots were at the same position at the start and they all spinned in the same direction, but they don't. If it makes you guys feel better, I made the same mistake the first time I tried to solve this.

SUCKMYMUSCLE

[suckmymuscle]

The 2 above posters are FAR more intelligent than I...
And even I can figure out that SMM answer is blatantly impossible.
SMM is not the kind of guy to admit hes wrong until the last minutes. Im not sure if he ever will, but if he does, itll be at the last possible minute just to try and save face.  

  I would give them props and admit that I was wrong, but I find their answer extremely implausible as well as simply simplistic as it ignores that the time of alignement of dots is only valid for the first spin.

SUCKMYMUSCLE

[Lumberjack88]

Let's make it visual.. so that you see how i started and what my axioms were:


This is the beginning. If we assume that all disks are transparent and that you only see their "red point" (although i use other colors for each disk), we can draw that picture from our premises. I've randomly put some disks to rotate clockwise, other disks rotate counterclockwise, but the most important part here is that this was a random process, i did not set these points up to fit my solution.
I've also chosen the alignment point randomly... It could've been on 90° or 187°, but i put it at 0° for the sake of simplicity.

The starting positions of each point was calculated by their constant angular velocity and the time they arrive at the green alignment point, which all these disks have in common, as given by the premises.

For example, Disk A was at the green point 2 minutes after start. So if you decide randomly that Disk A spins clockwise, you can go back 102° in the CCW direction from the green point, to find out where A was at the start (time = 0 minutes). Same applies to the other Disks... choose the spinning direction randomly and then you do some backtracing as shown above.



After nine minutes... this is where the dots are... Only A and E have reached the green alignment point at 9 minutes spinning time.

The alignment point was chosen randomly, so was the spinning direction. The starting points were calculated with the premises. I see no mistakes.

[lovemonkey]

Let's make it visual.. so that you see how i started and what my axioms were:


This is the beginning. If we assume that all disks are transparent and that you only see their "red point" (although i use other colors for each disk), we can draw that picture from our premises. I've randomly put some disks to rotate clockwise, other disks rotate counterclockwise, but the most important part here is that this was a random process, i did not set these points up to fit my solution.
I've also chosen the alignment point randomly... It could've been on 90° or 187°, but i put it at 0° for the sake of simplicity.

The starting positions of each point was calculated by their constant angular velocity and the time they arrive at the green alignment point, which all these disks have in common, as given by the premises.

For example, Disk A was at the green point 2 minutes after start. So if you decide randomly that Disk A spins clockwise, you can go back 102° in the CCW direction from the green point, to find out where A was at the start (time = 0 minutes). Same applies to the other Disks... choose the spinning direction randomly and then you do some backtracing as shown above.



After nine minutes... this is where the dots are... Only A and E have reached the green alignment point at 9 minutes spinning time.

The alignment point was chosen randomly, so was the spinning direction. The starting points were calculated with the premises. I see no mistakes.

Again wow, awesome! What's your university background? You have obviously done this before. This is one of the more solid pwnings I've ever seen on this board and that's saying a lot.

[Lumberjack88]

Again wow, awesome! What's your university background? You have obviously done this before. This is one of the more solid pwnings I've ever seen on this board and that's saying a lot.

I'm almost done with my electrical engineering bachelor. Been studying it here in Zurich at the swiss federal institute of technology, you know.. where einstein studied and made his phd

For me, this is not about owning anyone... I'm just interested in the correct solution, owning is just a byproduct of it

I'd really love to see suckmymuscle's visual explanation of this 5 disk system, it shouldn't be too hard to put the first 9 minutes into pictures... maybe there is truth to his solution after all.. although i highly doubt it... I just don't see how 9 minutes is the correct answer.

[lovemonkey]

I'm almost done with my electrical engineering bachelor. Been studying it here in Zurich at the swiss federal institute of technology, you know.. where einstein studied and made his phd

For me, this is not about owning anyone... I'm just interested in the correct solution, owning is just a byproduct of it

I'd really love to see suckmymuscle's visual explanation of this 5 disk system, it shouldn't be too hard to put the first 9 minutes into pictures... maybe there is truth to his solution after all.. although i highly doubt it... I just don't see how 9 minutes is the correct answer.

Aha! I sort of guessed you were some type of engineer. Electrical huh? Enjoying it so far? I'm thinking about studying that myself... I have about 6 months left till I have to make that decision and it's either between ordinary mechanical or electrical engineering for me.

Any pros/cons?

[Lumberjack88]

Aha! I sort of guessed you were some type of engineer. Electrical huh? Enjoying it so far? I'm thinking about studying that myself... I have about 6 months left till I have to make that decision and it's either between ordinary mechanical or electrical engineering for me.

Any pros/cons?

Well, what interests you more? I was always drawn to electricity, always liked gaming consoles, computers, audio technology, especially tube guitar amps etc., always wanted to know how these things function. So it was a no brainer for me. Mechanical engineering does contain big portions of electricity and vice versa, but if you're really more into cars, motors, mechanical systems in general, thermodynamics etc. you'd have to opt for mechanical engineering. Both is good, anyway.

If you appreciate pure theory and a broader perspective of things, you should definitely choose physics.

The problem with these studies is that they are all somewhat hard, and you have to really like what you do to succeed. Don't choose something you don't really really like. The good thing about hard studies is that everybody wants you after you're done with them... at least here in switzerland they value engineers and accept them in leadership positions even in financial institutions or assurances etc. Every firm needs logical thinkers, too many people in this world only learn by heart, they haven't really learned to use their brains.

[lovemonkey]

Well, what interests you more? I was always drawn to electricity, always liked gaming consoles, computers, audio technology, especially tube guitar amps etc., always wanted to know how these things function. So it was a no brainer for me. Mechanical engineering does contain big portions of electricity and vice versa, but if you're really more into cars, motors, mechanical systems in general, thermodynamics etc. you'd have to opt for mechanical engineering. Both is good, anyway.

If you appreciate pure theory and a broader perspective of things, you should definitely choose physics.

The problem with these studies is that they are all somewhat hard, and you have to really like what you do to succeed. Don't choose something you don't really really like. The good thing about hard studies is that everybody wants you after you're done with them... at least here in switzerland they value engineers and accept them even in financial institutions or assurances etc. Every firm needs logical thinkers, too many people in this world only learn by heart, they haven't really learned to use their brains.

When put that way, I'd say I'm more drawn to mechanical engineering.

Yeah, I've heard that too about engineers being very sought after in a big variety of situations and not just technical ones. Apparently a lot of executives have an engineering background. The pay is not even close to shabby either with very promising prospects..

There's just so many positives about engineering and that is what makes me want to study it besides my interest in mechanical stuff. It's definitely worth a couple of years of hell in school as you said.

Alright, I'll stop yapping.. good luck with your bachelors degree and we'll see what kind of bullshit response suckmyanus has got in store for you.

[suckmymuscle]

Yeah I don't think suckmymuscle even understands that these sort of problems are usually distributed in a setting where you have access to a computer...

  Here is where you go wrong. I am well aware of Wolfram's "Mathematica" and have used it since 2002. But this question cannot be solved with computer algorithms. The test designer, Hindemburg Melão, especifically created the questions of this test so that they can't be solved by computers. And distributed in a set where computers are used? Oh, really? This question is from the "Sigma Test", and online intelligence test where the questions were especifically created to minimize the help you get from extraneous sources. Also, the solutions to Melão's questions are a lot more elegant than what you got. Over a year to reach the configuration for the first time? I don't think so. My answer is a lot more elegant than yours. Given the difference in speed of rotation and direction, the red dot on disk one can be again at the position that corresponds to where the red dot reached the alignement point for the first time after nine minutes.

SUCKMYMUSCLE

[Captain Equipoise]

  Here is where you go wrong. I am well aware of Wolfram's "Mathematica" and have used it since 2002. But this question cannot be solved with computer algorithms. The test designer, Hindemburg Melão, especifically created the questions of this test so that they can't be solved by computers. And distributed in a set where computers are used? Oh, really? This question is from the "Sigma Test", and online intelligence test where the questions were especifically created to minimize the help you get from extraneous sources. Also, the solutions to Melão's questions are a lot more elegant than what you got. Over a year to reach the configuration for the first time? I don't think so. My answer is a lot more elegant than yours. Given the difference in speed of rotation and direction, the red dot on disk one can be again at the position that corresponds to where the red dot reached the alignement point for the first time after nine minutes.

SUCKMYMUSCLE

LOL, what the fuck is this supposed to mean !?!?! Hahahaha, it's not a beauty contest, face it you got owned

oh and Wolfram rocks!

[lovemonkey]

  Here is where you go wrong. I am well aware of Wolfram's "Mathematica" and have used it since 2002. But this question cannot be solved with computer algorithms. The test designer, Hindemburg Melão, especifically created the questions of this test so that they can't be solved by computers. And distributed in a set where computers are used? Oh, really? This question is from the "Sigma Test", and online intelligence test where the questions were especifically created to minimize the help you get from extraneous sources. Also, the solutions to Melão's questions are a lot more elegant than what you got. Over a year to reach the configuration for the first time? I don't think so. My answer is a lot more elegant than yours. Given the difference in speed of rotation and direction, the red dot on disk one can be again at the position that corresponds to where the red dot reached the alignement point for the first time after nine minutes.

SUCKMYMUSCLE

To have any credibility left you really do need to address the in-your-face pwning lumberjack88 delivered.

[cephissus]

Yes this:

 The problem is a tricky one, as most of the information given is irrelevant. The speed and direction of rotation of each disk is irrelevant as well as the fact that each dot is in a different position at the start of the movement, as this would only allow us to determine their relative positions in relation to one another if they had the same starting position as well as speed and turned in the same direction, clockwise or counter-clockwise. The only relevant information given are the amount of time each disk takes to turn - which absolutely makes the speed of rotation of the disks irrelevant. The fact that the time the disks take to spin is also given makes the information that some turn clockwise and others counter-clockwise irrelevant as well, since irrespective they will always be in the same position in the disk compared to the starting point! The final relevant information is that they all start spinning at the same time. We also know that at least 9 minutes have transpired since the disks started spinning, as this information is given. Taking into account all this, the solution is as follows: 9 minutes have transpired from the time the disks started spinning until the red dots on their surfaces were aligned. Explanation: since you know that at least 9 minutes have transpired since the disks started spinning, and since you can manipulate the speed and direction of rotations of the disks as you like and that they have different starting positions, you can align them whenever you want by manipulating the speed and direction of their rotation in the time alloted. This can be done to the intermediary disks, but since they all start spinning at the same moment, the size of the tiniest disk is relevant The only thing you need is to observe that the time it takes the largest disk to be at the minimum time alloted(9 minutes) coinceades with two minutes after the tiniest disk takes to complete a full 360 degree turn, which is 7 minutes. Two minutes after the smallest disks takes a full turn, it is once again at the point it was 2 minutes after it started spinning and that adds up to 9 minutes. Problem solved.

Is clearly more elegant than this:

main() {
 
        int answer = 0;
        int counter = 10;      
 
        while(answer == 0) {
                counter++;
                if ((counter-2)%7 + (counter-3)%13 + (counter-4)%17 + (counter-7)%19 + (counter-9)%23 == 0)
                   answer = counter;
        }
        
        printf("%i", answer);
 
}

when put through a C compiler, will solve the problem for you... the answer turns out to be 477,857 minutes.

 

[chaos]

LOL!!!! SMM being de-fucking-stroyed.

WAAAAAAAAAAAYYYY too much effort though LJ88.........although if that's your thing, you're doing it quite well.

[suckmymuscle]

  Yes, I am getting destroyed by the brilliant conclusion that it took over a year for the dots to be aligned for the first time. LOL!

  And the direction the disks spin change the relative position of the dots in relation to the places where they will be aligned on the other disks. It is not merely a matter of making the computer align the dots simply taking into account the amount of time they tak to spin on themselves and adding to that th amount of time each red dot takes ater each spin to reach the alignement position. It is not that simple. The test designer especifically made them spin asynchronously so that the solution couldn't be found so easily. Your answer is wrong.

SUCKMYMUSCLE

[suckmymuscle]

To have any credibility left you really do need to address the in-your-face pwning lumberjack88 delivered.

  There isn't any. His solution is wrong.

SUCKMYMUSCLE

[Lumberjack88]

 There isn't any. His solution is wrong.

SUCKMYMUSCLE

I'm not claiming that my solution is right, but the vast majority on here agrees with my solution and constantly tells you that 9 minutes doesn't make any sense.

You on the other hand claim to know that your solution is correct. So the burden of proof lies with you. And yet you only provided some sentences, that nobody on here seems to agree with. If your answer was really that correct and enlightening at least SOME people should have an "AHA! experience"... but NOBODY IN THIS WHOLE THREAD thinks your answer is logical.

Why don't you provide a visual explanation of your solution, so I can give you the kudos you supposedly deserve?

Because, again, right now, nobody agrees with your solution. And if the answer is correct, it SHOULD enlighten SOME people on here.
We're not talking about Quantum Mechanics solutions, this is just a normal logical problem that you can explain with showing where these points were at time=0, time=6, and according to you, time=9 they're all aligned.... the burden of proof lies with you. I've provided more than enough counterexamples.

[lovemonkey]

bump... sucky where are you?