Probability Questions (959)

An unbiased dice is rolled until a number greater than 4 appears. What is the probability that an even number of tosses is needed?

The odds against a certain event are 5:2 and the odds in favor of other event, independent of the former, are 6:5. Then find the probability that at least one of the events will happen.

Three coins are tossed once. Let A denote the event 'three heads show,' B denote the event 'two heads and one tail show', C denote the event 'three tails show' and D denote the event 'a head shows on the first toss', which events are mutually exclusive?

From an ordinary pack of 52 cards an even number of cards are drawn at random. Find the probability of getting equal number of black and red cards.

Two friends visit a restaurant randomly during 5 pm to 6 pm. Among the two, whoever comes first waits for 15 min and then leaves. The probability that they meet is:

Two aeroplanes I and II bomb a target in succession. The probabilities of I and II scoring a hit correctly are 0.3 and 0.2, respectively. The second plane will bomb only if the first misses the target. The probability that the target is hit by the second plane is

One function is selected from all the functions \(F : S \to S\), where \(S = \{1, 2, 3, 4, 5, 6\}\). The probability that it is onto function, is

Let \(A\) and \(B\) be two events such that \(P(\overline{A \cup B}) = 1/6\), \(P(A \cap B) = 1/4\) and \(P(\bar{A}) = 1/4\), where \(\bar{A}\) stands for complement of event \(A\). Then events \(A\) and \(B\) are

The boy comes from a family of two children; What is the probability that the other child is his sister?