Answer:
1/2
Step-by-step explanation:
Since this die has 6 sides, for each roll it has 6 outcomes.
Hence the probability of it landing on any specific number is 1/6.
Since there are only 3 outcomes wanted (roll less than 4 so it can be 1, 2, or 3) then we have to add the probability of each number being rolled so that is:
1/6 chance of rolling1
1/6 chance of rolling2
1/6 chance of rolling3
1/6 + 1/6 + 1/6
=3/6
=1/2
