4 Suppose that a fair die is rolled repetitively until at le

4. Suppose that a fair die is rolled repetitively until at least one odd number and one even number are observed. The total number of rolls N is recorded as the outcome of this random experiment. Note that the sample space for this experiment is 1-{1.2·.)

Solution

Probability = number of favourable events/number of exhaustive events

if there are n numbers in the sample space then half of them are odd and half of them are even

hence required probability = (n/2)/n = 1/2=0.5