In the simultaneous tossing of two perfect coins, the probability of having atleast one head is

An urn contains 9 balls, two of which are red, three blue and four black. Three balls are drawn at random. The chance that they are of the same colour is

If A and B are two independent events, the probability that both A and B occur is 1/8 and the probability that neither of them occurs is 3/8. The probability of the occurrence of A is

A number is chosen at random among the first 120 natural numbers. The probability of the number chosen being a multiple of 5 or 15 is

A single letter is selected at random from the word 'probability'. The probability that it is a vowel is

A coin is tossed three times in succession, the number of sample points in sample space is