You're playing a football on a desert island and want to toss a coin to decide the advantage. Unfortunately, the only coin on the island is bent and seriously biased. How can you use the biased coin to make a fair decision?

• keep the coin in one hand , show your two hands and let the one decide where it is.
• 10 years agoHelpfull: Yes(22) No(0)
• The only possible solution I can think of is:
  At first an area of 3x3 sq ft will be made in the sands and the coin will be hid in it. After doing so, one person from each team will be blindfolded and will be made to search the hidden biased coin. Whoever gets the coin first will win the 'toss'.
• 11 years agoHelpfull: Yes(7) No(9)
• The chance of one toss producing a head is different from the chance of it producing a tail, but the chance of two tosses producing a head then a tail is the same as the chance of two tosses producing a tail then a head. Allocate head-then-tail to one team and tail-then-head to the other, then keep tossing the coin in groups of two, ignoring double heads or double tails, until you get a result.
• 10 years agoHelpfull: Yes(6) No(0)
• We can use the coin as a whole, select two small 1ftX1ft areas A,B. Ask person from one team to place the coin in one of the areas A or B. Then let the other team guy choose A or B, if coin is guessed correctly he wins, or he loses.
• 11 years agoHelpfull: Yes(5) No(1)
• A member of team A randomly without seeing drop the coin into one of the two small boxes. Shuffles the box and ask Team B member to select. Since both the tosser and the other is opposite team is unaware of correct box, it serves the complete purpose of tossing a coin.
• 10 years agoHelpfull: Yes(2) No(2)
• on the Hand I will toss
• 10 years agoHelpfull: Yes(2) No(2)
• I would use ranking algorithm so that we could justify the probability of winning the toss.
• 10 years agoHelpfull: Yes(0) No(3)
• it seems to be contradictory "desert island" how is it possible??
• 10 years agoHelpfull: Yes(0) No(4)
• you can't predict still what will be the result after tossing the coin ...hide the face and toss it.no body knows the right answer to this thus fair decision.
• 10 years agoHelpfull: Yes(0) No(3)
• Simply give the coin in other hand and tell him to toss d coin and choose opposite of bent side...probably u will win d toss..
  OR
  There is no desert island
  
• 9 years agoHelpfull: Yes(0) No(0)
• The chance of one toss producing a head is different from the chance of it producing a tail, but the chance of two tosses producing a head then a tail is the same as the chance of two tosses producing a tail then a head. Allocate head-then-tail to one team and tail-then-head to the other, then keep tossing the coin in groups of two, ignoring double heads or double tails, until you get a result.
• 9 years agoHelpfull: Yes(0) No(0)
• On a desert surface, the coin will not bounce after hitting ground as in the case of a hard surface. The biased-ness of a coin comes into play when it bounces of a hard surface. In the air, the result is still unpredictable. One can simply toss it on sand.
  
  Or
  
  If the coin is seriously biased, don't use it, let the captains play odd-even with their fingers.
• 9 years agoHelpfull: Yes(0) No(0)
• calculate the probability and set according to that probability instead of original...
• 9 years agoHelpfull: Yes(0) No(0)