Suppose that a radio tube insrted into a certain type of set has a probability0.2 of functioning more than 500 hours. If we test 4 tubes, what is the probability that exactly three of these function for more than 500 hours,`.

Suppose we throw a die once. What is the probability of getting a number greater than 4 ?

Suppose we throw a die once. What is the probability of getting a number less than or equal to 4 ?

The following table gives life time of 400 neon lamps: A bulb is selected at random. Find the probability of that the life time of the selected bulb is less than 500 hours.

The probability of a shooter hitting a target is 3/4 . How many minimum number of times must he/she fire so that the probability of hitting the target at least once is more than 0.99?

A factory makes tennis rackets and cricket bats. A tennis racket takes 1.5 hours of machine time and 3 hours of craftman’s time in its making while a cricket bat takes 3 hour of machine time and 1 hour of craftman’s time. In a day, the factory has the availability of not more than 42 hours of machine time and 24 hours of craftsman’s time. What number of rackets and bats must be made if the factory is to work at full capacity?

Suppose a girl throws a die. If she gets a 5 or 6, she tosses a coin three times and notes the number of heads. If she gets 1, 2, 3 or 4, she tosses a coin once and notes whether a head or tail is obtained. If she obtained exactly one head, what is the probability that she threw 1, 2, 3 or 4 with the die ?

Two dice are thrown simultaneously 500 ties. Each time the sum of two numbers appearing on their tops is noted and recorded as given in the following table: If the dice are thrown once more, what is the probability of getting a sum: more than 10