<p>Somewhere in Northern Eurasia, a group of 20 lemmings is planning a special group suicide this year. Each of the lemmings will be placed in a random position along a thin, 100 meter long plank of wood which is floating in the sea. Each lemming is equally likely to be facing either end of the plank. At time t=0, all the lemmings walk forward at a slow speed of 1 meter per minute. If a lemming bumps into another lemming, the two both reverse directions. If a lemming falls off the plank, he drowns. What is the longest time that must elapse till all the lemmings have drowned?</p>
<p>I may have the correct answer. Not sure but i felt like posting this one because it seems so easy yet so hard.</p>
<p>answer (what i think. May be wrong) - DONT LOOK HERE <100S> DONT LOOK HERE</p>
<p>ANyhow I saw this on another forum and am just wondering. It seems very nice.</p>
<p>Anyhow lets start off with that one and another easy one</p>
<p>“I am the end of time and space. The beginning of earth. What am I?”</p>
<p>I love this riddle. So easy but does anyone want to do this?</p>
<p>Mr. and Mrs. Lewis attended a party one evening. Three other married couples were there; several handshakes took place. No one shook hands with himself/herself, no spouses shook hands, and no two people shook hands more than once. When Mr. Lewis asked each person how many hands he or she shook, the answers were all different. How many hands did Mr. and Mrs. Lewis each shake?</p>
<p>For the above — Handshakes are 0-6. The person who shook 6 hands shook with all other couples; his or her spouse can only shake 0 hands. Similarly, the 6 shaker shook hands with the 1 shaker, and that person’s spouse shook 5 hands. That leaves the third couple to shake 2 and 4 hands, and the last couple to both shake 3 hands. Since Mr. Lewis did not ask himself, if he were not a member of the 3-3 couple then he would have heard the same answer. We realize that Mr. and Mr. Lewis must be the 3-3 couple, so the each shook 3 hands.</p>
<p>You are in a prison. There are two doors. Behind one door is freedom. Behind another is a tiger. By each door is a gaurd. one gaurd ALWAYS lies and one ALWAYS tells the truth. You do not know which one is which. What ONE question to each of the gaurds can you ask that will ensure survival through the right door.</p>
<p>This one seemed interesting to me but I got it pretty fast…
There are 10 prisoners. They will be executed the next day. However they have a chance to live. On the execution day the prisoners will each be given a hat and can’t see the color of it. They will be lined up from 1 to 10 with 1 in the front and 10 in the back. 10 can see 1-9. However he can’t see his own. Each prisoner can escape if they guess the correct hat color of their own.</p>
<p>On the night before the execution they are allowed to meet. They can talk about w/e they want and they can develop a strategy.</p>
<p>You develop a strategy that gives the optimal probability of success</p>
<p>I can get it to .95 or 95% chance of survival for all prisoners. You guys?</p>