The ages of 30 workers in a factory are as follows
Age2425262728Frequency57846
(i) Find the probability that a worker selected at random is older than 25
(ii) Find the probability that the age of a worker is an odd number.
(iii) Find the probability that the age of a worker is an even number.
(iv) What is the sum of answers two and three? Why?
(i) Number of workers who are older than 25 = 8 + 4 + 6 = 18
Probability that a worker selected at random is older than 25 = 1830 = 0.6.
(ii) Number of workers whose age is an odd number = 7 + 4 = 11
Probability that age of a worker is odd = 1130
(iii) Number of workers whose age is an even number = 5 + 8 + 6 = 19
Probability that age of a worker is odd = 1930
(iv) Sum of answers two and three = 1130 + 1930 = 1. The sum is equal to 1 because the events are complementary and the sum of probabilities of complementary events is 1.