A die is thrown, find the probability of the events a. Getting a number less than 3, b. Getting a prime number.

Sample Space = {1 , 2, 3, 4, 5, 6}

n(S) = 6

a. Let A = Event of getting number less than 3.

∴ A = { 1 , 2 }

∴ n(A) = 2

∴ P(A) = n(A)/n(S)  = 2 / 6 = 1/3

b. Let B = Event of getting a prime number

B = {2 , 3 , 5 }

∴ n(B) = 3

∴ P(B) = n(B) /n(S) = 3 / 6 = 1/2