A pair of dice is thrown. What is the probability of getting the sum of numbers on the two faces an odd-prime number?

Two friends, P and Q, appeared in an interview for two vacancies for the same post. The probability of P's selection is $\frac{1}{3}$ and that of Q's selection is $\frac{2}{7}$. What is the probability that at least one of them will be selected?

Two dice are thrown simultaneously. What is the probability that 4 will come up on at least one die?

In a pack of lotteries, there are 5 prizes and 20 blanks. A lottery is drawn at random. The probability of getting prize is:

Two dice are thrown together. What is the probability that the sum of the numbers on the two faces is divisible by 4 or 6?

A basket contains 4 red, 5 blue and 3 green marbles. If three marbles are picked at random, what is the probability that at least one is blue?

Two persons A and B appear in an interview for two vacancies. If the probabilities of their selections are 1/4 and 1/6 respectively, then the probability that none of them is selected shall be: