Question

A coin is flipped four times. For each of the events described below, express the event as a set in roster notation. Each outcome is written as a string of length 4 from {H, T}, such as HHTH. Assuming the coin is a fair coin, give the probability of each event. (a) The first and last flips come up heads.

Answer 1

Answer:

{ (HHHH) (HHHT) (HHTH) (HTHH) (THHH) (HHTT) (HTTH) (TTHH) (HTHT) (THTH) (THHT) (TTTH) (TTHT) (THTT) (HTTT) (TTTT) }

P(first and last head) = 4/16 = 1/4