A speaks truth in 80%of the cases and B in 60% of the cases. The percentage of the cases of which they likely to contradict each other in stating the same fact is

Four tickets marked 00,01,11 respectively are placed in a bag. A ticket is drawn at random 5 times being replaced each time. The probability that the sum of the numbers on the tickets is 22 is

In each of a set of games it is 2 to 1 in favour of the winner of the previous game. The chance that the player who wins the first game shall win three at least of the next 4 is

Four persons entered the lift cabin on the ground floor f a 7 floor house. Suppose that each of them independently and with equal probability can leave the cabin at any floor beginning with the first. The probability of all 4 persons leaving at different floors is

An urn A contains 3 white and 5 black balls. Another urn B contains 6 white and 8 black balls. A ball is picked from A at random and then transferred to B. Then a ball is picked at random from B. The probability that it is a white ball is :

A, B, Care 3 news papers published from a city.20%of the population read A,16% read B,14% read C, 8% both A and C, 4% B and C,and2% read all the three. The percentage of then population who read at least one paper is

A bag contains 4 tickets numbered 1,2,3,4and another bag contains 6 tickets numbered 2,4,6,7,8,9. One bag is chosen and a ticket is drawn. The probability that the ticket bears the number 4 is

The odds that a book will be reviewed favorably by three independent critics are 5 to 2,4 to 3 and 3 to 4 respectively. The probability that of the three reviews amajority will be favourable is

A and B throw a pair of dice. A wins if he throw 6 before B throws 7 and B wins if he throws 7 before A throws 6. If A begins, his chance of winning is

There are 2 white, 4 black balls in urn A; In urn B, there are 5 white and 7 black balls. If one ball is randomly replaced from A into B , and a ball is drawn from B then the probabilty for the ball to be a white one is