Five Heads in a Row
Archives: Community Posts
Puzzle Prime is tirelessly looking all around the internet to find the very best puzzles and bring them all to puzzleprime.com.
Ant on a Cube
Suppose there is an ant in one corner of a cube. Every second, the ant moves from one corner to an arbitrary neighboring one along one of the three available edges. What is the expected time until the ant comes back to the starting corner?
Throwing a Hundred Sided Dice
Two people are taking turns throwing a hundred sided die. The game continues until someone throws a number larger than the number thrown by the opponent on the previous turn. What is the probability that the person who throws first wins the game?
Example: 4 – 3 – 3 – 2 – 5 => First player wins
Example: 6 – 3 – 2 – 1 – 1 – 4 => Second player wins
Chile to Singapore
You want to travel from Chile to Singapore. You find two sea captains – Jack and Will, which are willing to board you on their ships. Both of them depart from the same harbor early on the next morning, so you have to decide fast which one to hire.
Jack promises that he will arrive in Singapore on the 50th day of the cruise, at midnight. He will charge you $1 per hour for the trip. Will promises that he will also arrive on the 50th day of the cruise, at noon. He will charge you 1 cent per hour more than Jack. Both ships are in horrible conditions.
Which captain would you choose?
Remark: The first day of the cruise begins when the ship departs the harbor and ends 24 hours later. After that the second day of the cruise begins and so on.
