The following sample space shows all the possible outcomes for flipping 4 coins in a row, where H stands for heads and T stands for tails. If all 16 outcomes are equally likely, what is the probability that you flip: (4 marks) HHHH TTTT HTHH THTT HHHT TTTH HTHT THTH HHTT TTHH HTTH THHT HTTT THHH HHTH TTHT

a. All tails?

b. Exactly 1 tails?

c. An equal number of heads and tails? d. At least one head?