A student can attain grades A,B,C or D. Find the probability that the student can get at least B grade, if the probability of getting grade A is 0.20, grade B is 0.40, grade C is 0.30 and grade D is 0.10.

Two thirds of students in a class are boys and rest girls. It is known that the probability of a girls. It is known that the probability of a girl getting a first grade is 0.85 and that of boys is 0.70. Find the probability that a student chosen at random will get first grade marks.

a. The probability that a student will receive an A,B,C or D grade is 0.40, 0.35, 0.15 and 0.10 respectively. Find the probability that a student will receive: (i) not an A grade(ii) at most a C grade (iii) B or C grade. b. Neelam is taking up subjects Mathematics Physics and Chemistry. She estimates that her probabilities of receiving a grade A in these courses, are 0.2, 0.3 and 0.9 respectively. If the grades can be regarded as independent events, find the probabilities that Neelam receives, (i) All A,'s (ii) NO A's (iii) Exactly two A's

In an entrance test that is graded on the basis of two examinations,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 at least one of them is 0.95. What is the probability of passing both?

In an entrance test that is graded on the basis of two examinations, 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 at least one of them is 0.95. What is the probability of passing both ?

In an entrance test that is graded on the basis of two examinations, 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 at least one of them is 0.95. What is the probability of passing both?

In an entrance test that is graded on the basis of two examinations, 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 at least one of them is 0.95. What is the probability of passing both?

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?

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?