Answer
The sample space is
$S=\left\{(4,3), (4,2),(4,1), (3,4), (3,2), (3,1), (2,4), (2,3), (2,1), (1,4), (1,3), (1,2)\right\}$
Work Step by Step
The sample space is a set that consists of all the possible results of the experiment.
Here, at the first draw, all four slips of paper can be drawn from the box. At the second draw only the remaining three slips of paper can be drawn, therefore there will be $4\times3=12$ possible outcomes.
The sample space is
$S=${$(4,3), (4,2),(4,1), (3,4), (3,2), (3,1), (2,4), (2,3), (2,1), (1,4), (1,3), (1,2)$}
(the first number represents the first draw, the second number represents the second draw
