Question

When flipping 2 coins, which has the greatest probability:
a.) head, head
b.)tails, tails
c.) atleast one head
d.)heads, tail

Answer 1

Let's look at all possible outcomes: {HH, HT, TH, TT}, where H = heads, and T = tails. HH means two heads in a row, and etc.
You can see that there's only one outcome for HH, so your probability is 1/4. Likewise, TT also has a probability of 1/4. HT even has a probability of 1/4, since the order of results matters. But choice c.), at least 1 head, is satisfied for HH, HT, or TH. Therefore, its probability is 3/4.

Answer 2

Oh thanks :D