Rudolph flips two fair coins, each with a half probability of getting heads.
What is the probability he flips two tails in two tosses?
So I was thinking $0.5 + 0.5 = 1$, but I got it wrong.
I guess it doesn't make sense, because he could flip heads and then flip tails, or flip tails then flip heads, or flip two heads.
How do I find the probability? Do I subtract, or divide?