If one out of 10 coming ships is wrecked. Find the probability that out of five coming ships at least 4 reach safely.

The probability of any ship return safely to the port is 1/5 . Find the probability that the returning out of 5 ships, at least 3 ships returns safely. It is given that returning ships are independently.

Find the probability of getting at least one tail in 4 tosses of a coin.

The probability that a student is not swimmer is 1//4 . Then the probability that out of five students atleast four are swimmers is

The probability of happening an event A in one trial is 0.4. Find the probability that the event A happens at least one in three independent trials.

The probability of happening an event A in one trial is 0.4. Find the probability that the event A happens at least one in three independent trials.

The probabilities of two students A and B coming to the school in time are 3/7"\ " and 5/7 respectively. Assuming that the events, A coming in time and B coming in time are independent, find the probability of only one of them coming to the school in time. Write at least one advantage of coming to school in time.

Two coins are tossed. What is the probability of coming up two heads if it is known that at least on head comes up.

One in 9 ships is likely to be wrecked when they are set on a sail. When 6 ships are on sail, find the probability for i) atleast one will arrive safely ii) exactly three will arrive safely.

If on an average 1 vessel in every 10 is wrecked, the chance that out of 5 vessels expected 4 at least will arrive sefely is

Two dice are thrown simultaneously. What is the probability that : (ii) 4 will come up at least once ?