21.Let A, B, C be three equally likely anb collectively exhaustive events. if the odds 8 : 3 against A, 5 : 2 against B, then the odds against C are

22.Eight executives of a firm drive their cars to their office. The office is at liberty to park his car in any one of the three fields. The probability that there will be 5 cars of the above executives in field A, 2 cars in field B and 1 car in field C, on a randomly selected

23.In 324 throws of 4 dice, the expected number of times 3 sixes occur is

24.The probability that a teacher will give an unannounced test during any class metting is 1/5. If a student is absent twice, then the probability that the student will miss atleast one test is.

25.A fair coin is tossed 100 times. The probability of getting tails on odd number of times is