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Sword

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Everything posted by Sword

  1. Yes, that's the official answer. But not quite true of course as the poor can have many things that money can't buy. The rich crave for many things also. You can live connected to a drip without eating anything...
  2. It does work. Here is a video to prove it. I think the reason is as follows. The salt helps the ice to melt. Once some salt water is generated, it get diluted by the water already in the glass. The ice itself can be very cold, say -15 degrees and cause the water surrounding the string to refreeze.
  3. That's cheating somewhat. You didn't say you can use additional substances!
  4. What is greater than God, more evil than the devil, the poor have it, the rich need it, and if you eat it, you'll die?
  5. Diaconis, can we have the official answer please.
  6. I am not totally certain as I have not tried this before. Ice melts more easily as you put pressure on it. Hence the string can cut into the ice. Although the ambient temperature is more than zero degrees, the ice itself can still be -10 degrees. Hence, the water on top of the string will refreeze.
  7. Yes, I too realised the angle would be an additional variable. The first idea to come to mind is to express sin (angle) in terms of length and radius. But then it will get messy and rearranging to get the ratio of length/radius might be difficult or not feasible.
  8. I was thinking of doing it by a different way. The area of sector + the areas of the 2 segments. Rather curious if we can still remember the A level maths done decades ago. But on second thought, I would rather make some lunch instead.
  9. I started with the queen at a corner if that's allowed.
  10. Push the string onto the ice cube. The string will gradually cut into the ice. Water refreezes on top of string. Lift.
  11. It's much harder to do in your head!
  12. Hey, I am just about to post the answer:
  13. Grateful for small mercies.
  14. Let's hope the chief can keep his word better than our politicians...
  15. I am not certain I follow you. You pick a random robot and ask "Which door would the other robot say is the safe door?" If you have picked the truth telling robot, he will point to the death door (assuming he knows the other robot always lies). If you picked the lying robot, then he would also point to the death door (because he knows that the truth telling robot would point to the safe door and so he lies and point to the death door). Either way you go through the other door.
  16. I had my fun now and will let others have a go.
  17. The poles need to be touching.
  18. Which door would the other robot say is the safe door? Then whatever reply you get, go through the other door.
  19. A more tricky chess puzzle. White to move and wins material permanently by move 3. Material means the number of points. Queen = 9, Rook = 5, Bishop and Knight =3, Pawn =1.
  20. Turn on switch one for 5 mins. Then turn off and turn on switch two. Then open door. The bulb which is hot and off is controlled by switch 1. The bulb which is on is switch 2. The bulb which is off and cold is switch 3. Or you can just look through the gap at the bottom of the door or the key hole.
  21. You are right. I must have gone mad with cabin fever...
  22. B will take a7 and so pawn b7 is needed as 2nd move to mate
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