A coin is tossed. If it shows a tail, we draw a ball from a box which contains 2 red and 3 black balls.

The box contains 2 red balls and 3 black balls. Let us denote the 2 red balls as R1, R2 and the 3 black balls as B1, B2, and B3.

The sample space of this experiment is given by

S = {TR1, TR2, TB1, TB2, TB3, H1, H2, H3, H4, H5, H6}