$A$ coin is tossed. If it shows head,we draw a ball from a bag consisting of $3$ blue and $4$ white balls; if it shows tail,we throw a die. Describe the sample space of this experiment.

(N/A) Let us denote the blue balls by $B_1, B_2, B_3$ and the white balls by $W_1, W_2, W_3, W_4$.
The sample space $S$ of the experiment consists of all possible outcomes.
If the coin shows head $(H)$,we draw one of the $7$ balls. The outcomes are ${HB_1, HB_2, HB_3, HW_1, HW_2, HW_3, HW_4}$.
If the coin shows tail $(T)$,we roll a die. The outcomes are ${T1, T2, T3, T4, T5, T6}$.
Thus,the sample space is:
$S = \{HB_1, HB_2, HB_3, HW_1, HW_2, HW_3, HW_4, T1, T2, T3, T4, T5, T6\}$.