And then there is only one out of the four coins that's fair. So there was a 1 4 probability that I get a fair coin. Now, given that I have unfair, let's remind ourselves. An unfair coin has a 45% chance of coming up tails. So this means that I have a 45% chance of tails, which also means, and we have to be careful here because they're asking us about heads, if I have a 45% chance of getting tails, that means I have a 55% chance of getting heads. Whatever, I have 100% chance of getting one of these two. If it's 45% for tails, 100 minus 45 is 55 for heads.