A student appears for test I,II and III. The student is successful if he passes either in tests I and II or III. The students passing in tests I,II and III are p, q and 1/2respectively.Ifthe probability that the student is successful is 1/2 then

3 faces of a fair die are yellow, two faces red and one blue. The die is tossed 3 times. The probability that the colours yellow, red and blue appear in the second and third tosses respectively is

100 tickets are numbered as 00,01, 02,...,09,10,11,...99. When a ticket is drawn at random from them and if B is the event of getting 0 as the product of the numbers on the ticket, then P(B)=

I. In a class 25% of thestudents failed in mathematics, 30% failed in chemistry and 15% failed in both Mathematics and chemistry. If a student is selected at random failed in Mathematics, the probability that he failed in chemistry is 1/2

II: A bag contain 10 identical balls of which 4 are blue and 6 are red. 3 balls are taken out at random from the bag one after the other. The probability that all the 3 balls drawn are red is 1/6

If 2 numbers are randomly selected from 20 consecutive natural numbers, then the probability that the sum of the two numbers is an even number is

5 boys and 3 girls sit in a row at random. If a is the probability that all the girls sit together, b is the probability that all the boys sit together and c is the probability that all the boys and all the girls sit together then the ascending order a,b,c is

For a student the probability of getting a pass in one paper is75%and the probability of getting a pass in another paperis60%.The probability is 60% .The probability for the student to pass in one paper only is

In a class there are 60 boys and 20 girls. In it, half of the boys and half of the girls know cricket. The probability of a person selected from the class is either a boy or a person who knows ticket is

There are 10 stations between two cities A and B. A train is to stop at three of these 10 stations. The probability that no two of these three stations are consecutive is

I: A box contain 20 screws, 5 of which are defective, 2 screws are drawn at random.The probability of event that neither of the two screws is defective is 21/38.

II: A box contains 5 black, 4 white and 6 red balls. 2 balls are drawn without replacement. The probability that the first will be white and the second will be black is 4/21