Jump to content
BrainDen.com - Brain Teasers

rocdocmac

Members
  • Content count

    200
  • Joined

  • Last visited

  • Days Won

    11

Everything posted by rocdocmac

  1. rocdocmac

    16 Pawns puzzle

  2. rocdocmac

    9-Balls Cue

    A picture ...
  3. rocdocmac

    9-Balls Cue

  4. rocdocmac

    9-Balls Cue

  5. rocdocmac

    Killer quickie

  6. rocdocmac

    Killer quickie

    There are five people in a room, someone came and killed four. How many remains?
  7. rocdocmac

    Killer quickie

  8. rocdocmac

    Ants on an icosagon

    (a) If an ant is placed on each vertex of a regular isocagon, what is the probability that there will be no encounter between any two ants if all ants start moving simultaneously and randomly (either clockwise or anti-clockwise) along the edge to the next vertex without changing direction? What are the chances of no encounter if there are … (b) Four ants, each placed on the vertices of a tetrahedron? (c) Eight ants, starting at the corners of a cube?
  9. rocdocmac

    Ants on an icosagon

    CaptainEd ...
  10. rocdocmac

    Ants on an icosagon

  11. rocdocmac

    Twins birthday puzzle

  12. rocdocmac

    Twins birthday puzzle

  13. rocdocmac

    Ants on an icosagon

  14. rocdocmac

    Ants on an icosagon

    Should have said "isocagon" in the OP is wrong - icosagon in the title needs no change. Double dyslexia!!
  15. rocdocmac

    a^b x c^a = abca

    Thanks!
  16. rocdocmac

    Ants on an icosagon

    Sorry for the "icosagon" in the title! Should read isocagon. 'Twas a dyslexic moment!
  17. rocdocmac

    a^b x c^a = abca

    Trust so too! BN ... is there a way to work it out mathematically? I don't think that logarithms will suffice!
  18. rocdocmac

    MONEY

  19. rocdocmac

    a^b x c^a = abca

  20. rocdocmac

    Chess Board Puzzle

    Looks like cheerio to this one!
  21. rocdocmac

    Chess Board Puzzle

    Use the twelve pieces on the left to create a chess board, The pieces may be flipped!
  22. rocdocmac

    3 Quickies

    Merci beaucoup Harey et bonne nuit ...
  23. rocdocmac

    3 Quickies

    10 minutes each! 1. A bag holds four counters. One of them is white. Each of the others is either black or white at equal chance. One randomly draws out two counters, and discover they are both white. If one then randomly draws a third counter, what is the chance that it is white? 2. I’m about to play the music songs on Side 1 of a standard LP (diameter = 292 cm) that contains six tracks. The recorded surface area is 487.6 dm2 (including the “gaps” between each song) and the average distance between each annulus (i.e. distance between each “groove” along the LP radius) is 197 µm. The total time that it will take to play this side right from the beginning of the first song to exactly the end of the last (6th) song is 18:04 minutes. If the “needle” (stylus) is poised 12.5 mm directly above the beginning of the first song and 2 mm away from the edge of the record, how far does the “needle” travel to the point where the last song just ended? 3. What comes next? 6 1 3 1 4 _
  24. rocdocmac

    3 Quickies

    @harey... Êtes-vous Franҫais?
  25. rocdocmac

    3 Quickies

    The needle goes down 12.5 mm to the very beginning of the first song, i.e. before the first song actually starts.
×