Describe the sample space for the indicated experiment : A coin is tossed and then a die is rolled only in case a head is shown on the coin.

Solution: When we toss a coin, there is possibility either head will come or tail will come.
If head comes, then dice will be rolled. Then, there can be 6 out comes.
In that case, possible outcomes $H1,H2,H3,H4,H5,H6$.
If, tail will come, nothing will be done. So, here is only a single outcome.
In that case, only possible outcome is $T$.
So, sample space will be $=6+1=7$