A man and his wife appear in an interview for two vacancies in he same post . The probability of husband's selection is (1/7) and the probability of wife's selection is (1/5) . What is the probability that only one of them us selected ?
A speaks truth in 75% cases and B in 80% of the cases . In what percentage of cases are they likely to contradict each other narrating the same incident ?
Two dice are tossed . The probability that the total score is a prime number is :
In a class , 30% of the students offered English , 20% offered Hindi and 10% offered both . If a student is selected at
random, what is the probability that he has offered English or Hindi ?
A box contains 20 electric bulbs , out of which 4 are defective . Two bulbs are chosen at random from this box.The probability that at least one of these is defective is :