The probability that a student passes a physics test is `2/3` and the that he passes both a physics and English test is `14/25`. The that he passes at least one test is `4/5`. What is the probability that he passes the English test.

In on examination the probability of a student passed in physics is 2/3 , passed in both English,and physics is 14/45, If the probability of passing at least one subject is4/5 , find the probability of passing in English?

The probability that a candidate passes in physics is 70% and that the passes in chemistry is 40% . What is the probability that the candidate passes in any one of the two subjects ?

In a test an examine either guesses or copies or knows the answer to a multiple choice question with four choices. The probability that he makes a guess is 1/3 and the probability that the copies the answer is 1/6. The probability that his answer is correct, given that he copied it, is 1/8. Find the probability that he knew the answer to the question, given that he correctly answered it.

In an entrance test that is graded of the basis of two examination, the probability of a randomly chosen student passing the first examination is 0.8 and the probability of passing the second examination is 0.7. The probability of passing atleast one of them is 0.95. What is the probability of passing both?

The probability that a student will pass the final examinatin in both English and Hindi is 0.5 and the probability of pasing neither is 0.1. If the probability of passing the English examination is 0.75. What is the probability of passing the Hindi examination?

For a student to qualify, he must pass at least two out of three exams. The probability that he will pass the 1st exam is p. If he fails in one of the exams, then the probability of his passing in the next exam, is p/2 otherwise it remains the same.Find the probability that he will qualify.

The probability that a contractor will get a plumbing contract is (2)/(3) and the probability that he will not get an electric contract is (5)/(9) ,if the probability getting of at least one contract is (4)/(5) then what is the probability that he will get both the contract?

In answering a question on a multiple choice test, a student either knows the answer or guesses. Let (3)/(4) be the probability that he knows the answer and (1)/(4) be the probability that he guesses. Assuming that a student who guesses at the answer will be correct with probability (1)/(4) . What is the probability that the student knows the answer given that he answered it correctly?

40% of the students in a class are girls. If 60% and 70% fo the boys and the girls respectively of the class pass a certain test, what is the probability that a randomly selected student from the class will have passed the test?

The probability that a teacher will give a surprise test during any class meeting is (1)/(5) . If a student is absent on two days, what is the probability that he will miss at least one test ?