Two coins are in a jar. Although I can’t tell them apart, I know
that one coin is fair (it has a probability of 1/2 of landing on
heads) and the other is NOT fair (it has probability 1/4 of landing
on heads). One of the coins is randomly selected from the jar. Call
this selected Coin C.
(a) Coin C is tossed twice. It is heads on both tosses. Given
this information, what is the probability that Coin C is the fair
coin?





