Bag with 100 coins. One of them is double headed, the rest are fair. You flip it n times and get n heads. What would your intuition be on whether you have the double headed coin or not?
What would the probability be that you have the double headed coin be as n goes to infinity?
How many flips would it take for you to be 50% sure?
You flip it seven times, what is the probability you have the double headed coin?