Here are the sample spaces of a few standard probability experiments that we have been and will be discussing:

Drawing a card at random from a standard 52-card deck

Obviously the sample space is the 52 cards in the deck; but it can be useful to have the image (from wikipedia):

Rolling a pair of six-sided die

Since there are 6 possible outcomes for the 1st die and 6 possible outcomes for the 2nd die, there are 6*6 = 36 outcomes in the sample space. It is useful to arrange these outcomes in a 6-by-6 matrix:

(1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6)
(2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6)
(3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6)
(4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6)
(5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6)
(6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6)

Flipping a coin 2 times in a row

In this experiment, there are 4 distinct outcomes in the sample space:

S = {HH, HT, TH, TT}

If we consider the experiment of flipping a coin 3 times in a row, there are 2^3 = 8 distinct outcomes in the sample space:

S = {HHH, HHT, HTH, HTT, THH, THT, TTH, TTT}

Exercise: You should try to draw these two experiments/sample spaces as tree diagrams! Also try to write out the sample space for the flipping a coin 4 times in a row. Hint: there are 2^4 = 16 distinct outcomes in that sample space.