Test your skills of deduction with the June 2022 edition of Riddle Me This: Three Coins
Your friend wants to play a game. You are to turn your back as your friend places three coins, a nickel, a dime, and a quarter on a table behind you. He can arrange them in any pattern of heads or tails as long as they are not all the same. You then tell your friend to flip the coins any way you would like. For example, you can say “flip the dime” or “flip all three coins,” etc. Your goal is to get all three coins to be the same, either all heads or all tails. As soon as all three coins are the same, your friend will tell you that you’ve won.
What is the best strategy to use to win the game in the fewest number of steps possible?
Click to Reveal Answer
I don’t see how it works, what am I missing
H, T, T
Flip 1 and 3
T, T, H
Flip 1
H, T, H
Flip 1 and 3
T, H, T
Kevin
When you made your last move, you accidentally flipped 2 as well.
Fewest number of steps seems to be to have your friend to flip the one that is different to be the same as the other two.
Exactly the same procedure but less complicated is this:
1. Flip the dime
2. Flip the quarter
3. Flip the dime again
Guaranteed to win in three moves or less. Initial state is that two are the same and one is different. If the dime was different, you win on move one. If the nickel was different, you win on move two. If the quarter was different, you win on move three.
1. Flip the nickel
2. Flip the nickel and the dime
3. Flip the nickel
…also works for a three step solution with one fewer coin flip.
would this work with fifty dollar bills? Could be a good money maker.
As you can see below, the it all depends on the original setup. However, the solution for “best strategy” is on point as you will win regardless in three moves at 33% of the time, 33% in two moves and 33% in one moves.
Heads or Tails is irrelevant below but is addresses all the possible scenarios.
Going to find someone that will play with $50 bills.. 🙂
SETUP NDQ FLIP N Q FLIP N FLIP N Q
H T H T T T WIN
H H T T H H H H H WIN
H T T T T H H T H T T T WIN
T H T H H H WIN
T T H H T T T T T WIN
T H H H H T T H T H H H WIN