Solution:
We know that,
In throwing a dice, total possible outcomes = {1, 2, 3, 4, 5, 6}
So, n(S) = 6
(i) On a dice, numbers less than 3 = {1, 2}
So, n(E) = 2
Hence, probability of getting a number less than 3 = n(E)/ n(S) = 2/6 = 1/3
(ii) On a dice, numbers greater than or equal to 4 = {4, 5, 6}
So, n(E) = 3
Hence, probability of getting a number greater than or equal to 4 = n(E)/ n(S) = 3/6 = 1/2