Coin Flip and calling randomly

#1
If there is a coin flip contest and there is a coin flipper continuously flipping the coin and there are three contestants
1. Always Calls Heads
2. Always Calls Tails
3. Calls randomly

what is the percentage of right answers for each contestants and why. I think its 50% for always heads guy and always tails guy and zero for the random guy but my friend thinks its 50% for everyone but both of us are confused can someone
help us understand probabilities

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Thanks.
 

Dason

Ambassador to the humans
#4
Let's do a thought experiment. Let's pretend that these three contestants actually exist. You're telling me that you think the guy that chooses randomly will have a "small" percentage of winning long term - let's just say that it is somewhere between 0 and 50%. That meant that if I became a contestant and *my* strategy was just "call the opposite of whatever the guy choosing randomly calls" that I would have a high percentage of winning - somewhere between 50% and 100% (because every time that guy lost I would win and every time he won I would lose).

Does that seem odd to you?
 

ted00

New Member
#5
What's the probability that person 3 calls heads? Is the event that person 3 calls heads independent of the event that the coin lands on heads? ;)