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  • #16
    I see. Excellent - you have pretty much solved it, except my answer is 7 fewer than yours, because I meant that there is only one white, one yellow,..., one black - not two of each. (I'm not sure why you thought two - perhaps my wording "one each of a white ball, yellow, green, brown, blue, pink and black balls" is a bit ambiguous, ending as it does in "balls"? But how do you expect to play with two white balls - this is Nookers, not Billiards!)

    Anyway, subtract 7 from your answer and we agree (except, you have not quite proved that your answer is the only one possible, which it is)!



    So, on to question 5:

    ----------------------------------------------------------------------
    Q5)

    Around the time of the 200,007 Crucibilis Nookers Plus Final, one of Crucibilis's best players, Sonny O'Jollyman had got bored with potting his shrubs and was playing a tournament of 962,537,588,106-Ball pool. This delightful game is played on a smiliar table to a Nookers table, only smaller, but with bigger pockets - pockets the size of Pluto (the planet-and-soon-possibly-not-to-be-a-planet, that is, not the cartoon dog) - and the same number of balls (some the size of grapefruit, some the size of ripe tomatoes).

    Each ball, except the white, is numbered from 1 to 962,537,588,106, which the players have to strike (with the white) in order, the winner being the one who pots the 962,537,588,106-ball.

    While Sonny was about to play his long-time best pal, Ebbie Petdon, in the Final, it was the job of the delightful referee, Tabitha Michaels, to keep the balls clean, something which the spectators loved to watch. Unfortunately, with so many balls to clean, her gloves got rather dirty and it so happened that, while wiping a ball that was dirty made it clean, when she wiped a ball that was already clean she actually made it dirty!

    At the start of the Final, all the balls were dirty (as Haggis Allixins had dropped beer on them during his thrilling comeback against Jammy Brown in the Semi-Final). So Tabitha first wiped every ball and made it clean. (She never wiped the white ball again.)

    Ebbie wasn't satisfied, so asked that she clean some again. In fact, she then wiped only every ball divisible by 2. Sonny didn't think this was sufficient, so asked that she wipe some again, and this time she then wiped every ball divisible by 3. In fact, this continued, with her then wiping every ball divisible by 4, then every ball divisible by 5,..., through to 962,537,588,106.

    By the time she had finished, the audience had gone home, because much as they enjoyed watching her polishing the balls, enough was enough, and the match was never played.

    However, if the players had then started, how many clean balls would there have been on the big 962,537,588,106-Ball table?
    "If anybody can knock these three balls in, this man can."
    David Taylor, 11 January 1982, as Steve Davis prepared to pot the blue, in making the first 147 break on television.

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    • #17
      Well. Question 6:

      Several snooker fans are cogitating over some inconsequential mathematical quiz, and have some answers 'whitened' out by changing font colour which can then be seen by highlighting the invisible text.

      Which one is the sadder?

      Answer: Any who are having such discussion at ten past twelve on a sultry Sunday July morning!

      I laugh sarcastically here, but I realise that it could just as easily have been me, if I'd been here

      Comment


      • #18
        Ah that's it, for some reason I understood 'one each' as 'one for each player'. It'd make an interesting game, don't you think? Trying to knock your opponent's colours safe while breakbuilding with your own (as long as it doesn't lead to a rerack that is, that could take some time).

        Back to the numbers; proving something has only one solution I can deal with, proving it only has one integer solution is something I can't fathom how to approach (integers don't mean much in applied maths, it's new territory for me ). It's clear a can't be odd, because then you'd have odd over even, but other than that, I'm stumped. I'll have another look tomorrow.

        For question 2 I got to the answer by working backwards from 40 and taking the chops I needed, but I can sort of see now why the answer's so elegant. Is there an elegant method/reasoning too?


        Since nobody else seems to be online I'll leave Q5 until tomorrow, give abextra and others a chance to see it, and sign off for the night. Thanks for taking my mind off, um, other things we won't mention.

        Comment


        • #19
          May I just ask every witch to show me a wrong path? The two liars have to point at the right one...

          Comment


          • #20
            Originally Posted by abextra
            May I just ask every witch to show me a wrong path? The two liars have to point at the right one...
            Unfortunately not! You may ask the witches questions to which they may only cackle Yay or Nay in response - you cannot ask them to point! (With their gnarled hands you wouldn't be able to see where they were pointing, anyway.)
            "If anybody can knock these three balls in, this man can."
            David Taylor, 11 January 1982, as Steve Davis prepared to pot the blue, in making the first 147 break on television.

            Comment


            • #21
              Originally Posted by Robert602
              ...Back to the numbers; proving something has only one solution I can deal with, proving it only has one integer solution is something I can't fathom how to approach (integers don't mean much in applied maths, it's new territory for me ). It's clear a can't be odd, because then you'd have odd over even, but other than that, I'm stumped. I'll have another look tomorrow.


              Good luck. Once you've got there - or if you give up (hopefully not) - here is a proof that it is the only answer. Hopefully, this will appear in "hidden text" (which you can view by selecting it, if I've mastered the technology)!

              ( Let the square in Nookers be of x^2 reds, i.e. x rows and x columns.

              Then the rectangle in Nookers Plus has x+991 rows of reds.

              So x^2 must be divisible by x+991.

              Dividing x^2 by x+991, we get x-991, remainder 991^2, i.e.

              x^2 = (x+991)(x-991) + 991^2

              Since x^2 is divisible by by x+991, 991^2 must also be divisible by x+991.

              Since 991 is a prime number, the only factors of 991^2 are 1, 991 and 991^2.

              Therefore x+991 = 1, 991 or 991^2.

              The only solution for x>0 is:

              x+991 = 991^2.

              So x= 991^2 - 991 = 991 x 990 = 981,090

              and x^2 = 962,537,588,100

              Now add the other 7 balls (the white and 6 colours).

              So the answer is 962,537,588,107

              )



              And question 5 is still out there!
              "If anybody can knock these three balls in, this man can."
              David Taylor, 11 January 1982, as Steve Davis prepared to pot the blue, in making the first 147 break on television.

              Comment


              • #22
                Joining the dots... or squaring the circle?

                While you play with question 5, let me throw question 6 into the mix:

                ------------------------------------------------------------------------

                Q6) Draw a picture of cue ball on a piece of paper. (This should look like a circle!)

                Now, you must put some dots on the circumference of the circle and join up the dots with straight lines, so that they divide the circle into as many different regions as possible.

                With 1 dot (and some may think that 1 dott is more than enough), there are no lines to draw, and the circle has just 1 region inside it.

                With 2 dots, there is one line to draw, and the circle is divided into 2 regions.

                With 3 dots, you should be able to draw 3 lines forming a triangle inside the circle, dividing the circle into 4 regions.


                Finally, onto the question:

                How many regions can you make when the number of dots is equal to:

                a) the lowest ever number of frames won in a Crucible semi-final by the loser;

                b) the number of UK Championships won by Stephen Hendry;

                c) the number of UK Championships won by Steve Davis;

                d) the number of World Championships won by Stephen Hendry?
                "If anybody can knock these three balls in, this man can."
                David Taylor, 11 January 1982, as Steve Davis prepared to pot the blue, in making the first 147 break on television.

                Comment


                • #23
                  Q5) Is it possible that there would have been 981091 clean balls? If I'm wrong then please give a hint!
                  Q6) a)4 b)16 c)8 d)57

                  Comment


                  • #24
                    Almost there!

                    Originally Posted by abextra
                    Q5) Is it possible that there would have been 981091 clean balls? If I'm wrong then please give a hint!
                    Q6) a)4 b)16 c)8 d)57
                    Good work, abextra!

                    Q5) It is more than "possible"... that is the exact number of clean balls. Would you care to give a proof?

                    Q6)
                    I agree with you on parts b) and d).

                    Part a), I suspect that you and I disagree over the fewest frames ever won by a loser in a Crucible semi-final. I thought it was 4, when Hendry lost 17-4 to O'Sullivan in 2004. Has anyone ever won only 3 frames?

                    Part c) - I'm pretty confident that Davis has 6 UK Championship titles.... care to revise your answer to this one?


                    So.... 1, 2, 4, 8, 16.... is there a pattern?
                    "If anybody can knock these three balls in, this man can."
                    David Taylor, 11 January 1982, as Steve Davis prepared to pot the blue, in making the first 147 break on television.

                    Comment


                    • #25
                      Hi,DG!

                      Q6) a) Sorry, I know very little about history of snooker,my data is from Wikipedia.There is written, that in 1974 Fred Davis lost to Ray Reardon 3 - 15 in semis.

                      Q5) I will do my best to give a proof, DG, but I have to warn you, that it will be painful for both of us, because my English is very bad. ,I never learned math in English and I have serious doubts about the words I have to use. Anyway,if the ball was clean or dirty in the end depends on how many times it was wiped. Those balls ,which were wiped odd number of times (1, 3, 5...) ,should be clean and those ,which were wiped even number of times ,should be dirty. The number of wipings depends on how many factors does a number have (I mean, for example number 10 has 4 factors - 1, 2, 5 & 10, ball number 10 will be wiped 4 times and will be dirty, number 25 has 3 factors - 1, 5 & 25 , ball number 25 will be wiped 3 times and will be clean, etc.) Most numbers have even number of factors ( they are forming a pairs(at least they do it in my country)), exceptional are numbers which are squares of some other number (1, 4, 9, 16...100, 121, 144...etc.)The biggest square number less than 962537588106 is 962537588100, which is square of 981090 ( I just took the square root of the number of balls).It means that there are 981090 square numbers, it is 981090 clean balls plus white ball,which is clean too.

                      Comment


                      • #26
                        Q6) c)You're absolutely right, DG, Davis has 6 UK Championship titles. I missed the first two times he won, I'm afraid it wasn't ranking event then and thats why those wins were mentioned in other place.I'm very sorry...
                        The only pattern I see tells me that the next number must be 32, but with 6 dots I can't find more than 30 regions.

                        Comment


                        • #27
                          Hello abextra!

                          Q5) I understood the proof perfectly - and the answer is correct! As you say, it hinges on the fact that square numbers have an odd number of factors and non-square numbers (positive integers) have an even number of factors. (If k is a factor of n, then n/k is also a factor of n, and will be different from k unless n=k^2. So the factors all come in pairs, except where n is a perfect square.)

                          Q6 a) The first championship at the Crucible was in 1977. That is why Fred Davis's score does not count.

                          The pattern so far is then 1, 2, 4, 8, 16,... I can assure you that the number that comes next is more than 30 regions, but what is it?!
                          "If anybody can knock these three balls in, this man can."
                          David Taylor, 11 January 1982, as Steve Davis prepared to pot the blue, in making the first 147 break on television.

                          Comment


                          • #28
                            Good evening, davis_greatest!

                            Q6) a) I think I have to learn to read.

                            This pattern is powers of 2 - 2^0, 2^1, 2^2, 2^3, 2^4 and the next is 2^5 which is 32, then will be 64, 128, 256 etc.

                            Comment


                            • #29
                              Sadly, no! It looks like there is a "pattern", after 1, 2, 4, 8, 16 - but that is where it breaks down! The next number is not 30 ... and it is not 32 either! Sometimes apparent patterns can be misleading

                              Interestingly, the number 256 does appear - but whereas you might think it would come 9th (if the pattern were 1, 2, 4, 8, 16, 32, 64, 128, 256,...), it in fact comes 10th!

                              You were right that 57 is the 7th number!
                              "If anybody can knock these three balls in, this man can."
                              David Taylor, 11 January 1982, as Steve Davis prepared to pot the blue, in making the first 147 break on television.

                              Comment


                              • #30
                                But this is still a pattern - 1, 2, 4, 8, 16, x, 57, y, z, 256, ,,,( x > 30 ) ? I mean, there must be some kind of regularity?

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