Probability Tes...

A biased coin with probability p, 0 < p < 1, of heads is tossed until a head appears for the first time. If the probability that the number of tosses required is even is 2/5, then p =

The probability of a bomb hitting a bridge is 1/2 and two direct hits are needed to destroy it. The least number of bombs required so that the probability of the bridge being destroyed is greater than 0.9 is

In a binomial distribution, the mean is 4 and variance is 3. Then its mode is

A die is tossed thrice. If getting a four is considered a success, then the mean and variance of the probability distribution of the number of successes are

A die is tossed twice. Getting a number greater than 4 is considered a success. Then the variance of the probability distribution of the number of successes is

A die is thrown three times. Getting a 3 or a 6 is considered success. Then the probability of at least two successes is

In a simultaneous toss of four coins, what is the probability of getting exactly three heads

A coin is tossed successively three times. The probability of getting exactly one head or 2 heads, is

The items produced by a firm are supposed to contain 5% defective items. The probability that a sample of 8 items will contain less than 2 defective item is

The probability that a man can hit a target is 3/4. He tries 5 times. The probability that he will hit the target at least three times is