BrainDen.com - Brain Teasers

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1. Past hour
2. ## Sequence puzzle

Thank you. He did figure it out after I posted.
3. Today

5. ## The Executioner's Riddle

Good guess . . . Right track. Go lower : )
6. ## The Executioner's Riddle

I'll count being in any way confused for Shakee as high praise. As for this one
7. Yesterday
8. ## The triangle puzzle

You've probably seen this puzzle. There are 15 holes in triangular array. (See sketch below.) The game begins with pegs in 14 of the holes. The play is to jump pegs over adjacent pegs, removing the "jumped" pegs afterward, as in checkers. The jump is made in a straight line. To make a jump, you need a contiguous group consisting of { peg1, peg2, hole } in a straight line. Peg1 ends up in the hole, and peg2 is removed. The object is to make 13 legal jumps and end up with a single peg. This happens about 6% of the time. That is, about 94% of the time you get a configuration, with more than one peg remaining, that permits no further legal jumps. In some games the peg must end up in the original empty hole, and that happens only about 3% of the time. So, it's not a trivial puzzle. This puzzle asks for something different, and easier: Lose as badly as possible. That is, select a location for the empty hole, and then find a sequence of moves that leaves the greatest number of pegs on the board where there are no more legal jumps. It's simple enough to play, even without the game, by marking hole locations on a sheet of paper and using pennies. As already stated, there are 15 holes. There are also 36 possible jumps. For convenience in writing sequences of jumps, they can be numbered, as follows: Number the jumps like this: and the holes ---------------------------> o ------------- 1 So Jump #1 means the / \ like this: peg in hole #1 jumps 1 2 ----------> 2 3 over the peg in hole #2 into the empty 4 5 6 hole #4. o o / \ / \ 7 8 9 10 Jump #18 is peg 7 3 4 5 6 over peg 8, into 7 13 11 12 13 14 15 hole 9. / \ o-8 o 14-o Holes 4, 6, 13 / \ / \ / \ begin 4 jumps; 9 10 11 12 15 16 the others 17 19 21 23 begin two. / / \ \ o-18 o-20 22-o 24-o There are 36 jumps. 25 27 29 30 33 35 / / \ / \ \ o-26 o-28 31-o-32 34-o 36-o With symmetries taken into account, the holes have four equivalence classes: Corners (1, 11, 15) Adjacent to corners (2, 3, 7, 10, 12, 14) Edge centers (4, 6, 13) Centers (5, 8, 9) This means that there are just four distinct places for the empty hole to start a game: { 1 2 4 5 }. All other holes are symmetrically equivalent to one of these. Just to be sure the numbering above is understood, here is a winning game of the normal type. Start with pegs in every hole except #1. (The top hole is empty.) Then make these jumps: { 7 14 2 17 23 27 34 26 30 6 35 14 7 }. If done correctly, the original hole #1 contains the final peg. Enjoy.
9. ## Shakeepuddn    plainglazed

Is there an archive such that we (or moderators) can contact old members and urge them back into the swing?  This site used to rock with traffic and great riddles/puzzles.  Still great material but it's like a ghost town now.

10. ## The Executioner's Riddle

Sorry, not it. And youre confusing me with plasmid, I believe.

Spot on!
12. Last week

15. ## The Executioner's Riddle

What happened to your "I'm not a..." titles, Shakee? Those were so good! An opening guess, in any case.
16. ## One Girl - One Boy

Old thread, and masses of discussion, but to simplify - There are 4 equally likely combinations of 2 children: Boy/Boy; Girl/Girl; Boy/Girl; Girl/Boy. The odds of the second child being a girl depend upon how the OP is interpreted and the possible combinations (green) each interpretation allows. 1. They have two kids, [only] one of them is a girl. Boy/Boy Girl/Girl Boy/Girl Girl/Boy - Trick question. In the 2 possible combinations the other child must be a boy. Probability 0. 2. They have two kids, [the first] one of them is a girl. Boy/Boy Girl/Girl Boy/Girl Girl/Boy - There are 2 possible combinations where the first child is a girl. In 1 the other child is too. Probability 1/2. 3. They have two kids, [at least] one of them is a girl. Boy/Boy Girl/Girl Boy/Girl Girl/Boy - Without the Boy/Boy combination 3 remain, in 1 of which the other child is a girl. Probability 1/3.
17. ## Sequence puzzle

I am trying to help my son solve a sequence puzzle. I tried the "read the line" on this one and still can't figure it out. The below is a number puzzle. It should be read left to right, top to bottom. Question 1 What is the next two rows of numbers. Question 2 How was this reached. 1 1 1 2 1 1 2 1 1 1 2 3 1 1 3 1 2 2 1 ? ?
18. ## The Executioner's Riddle

I bite when bitten Smite the smitten Hang the lowly Who die so slowly My eyes request The tougher test So shed your doubts And cast me out
19. ## Hot Love Riddle

Well done, Sir! I'm collecting these and trying to keep them a little easier than our previous forays into literature, history, arcane items, and whatnot. Cheers!
20. ## Hot Love Riddle

Pretty sure it's one of these
21. ## Crypto-anagram

Apology ... a little mistake in the third word. It should read EWTUFRFUXCJZ (one "F" was missing). So here is the correct one: ABRQQNA WTKQXT EWTUFRFUXCJZ﻿ GNUZCUWCAS
22. ## Fair deal?

Assuming everyone ate the same number of rolls…

24. ## Fair deal?

[If appeared before in any other form, please delete this question, Mr Moderator} Alpha and Bravo were having a meal with eight bread rolls in the kitty. Alpha contributed five of those rolls, whereas Bravo brought along three. Charlie (as a third person) joined them for the meal, but gave Alpha and Bravo eight coins (as compensation) afterwards. Bravo demanded a 50/50 share of that compensation, even though Alpha offered Bravo three coins, thereby keeping five coins for himself. What should the distribution of Charlie's coins be to make it truthfully a fair deal?
25. ## Hot Love Riddle

Hey plasmid! Long time! Funny, volcano was my friend's first guess. But they don't swallow, paticularly when force fed : )
26. ## Crypto-anagram

Here is a cryptogram: ABRQQNA WTKQXT EWTUFRUXCJZ GNUZCUWCAS Solve it, then unscramble the letters in the resulting sentence (it is now an anagram) to reveal the name and surname of a politician and two of his policies (there are four words).

28. ## Hot Love Riddle

Cats tend to be sort of lazy by nature, so that's my excuse. But to kick things off

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