Q39 of 43 Page 15

(iii) P(A or B)


(i) P(not A) = 1 – P(A)

                = 1 – 0.42 = 0.58

(ii) P(not B) = 1 – P(B)

                 = 1 – 0.48 = 0.52

(iii) P(A or B) = P(A ∪ B)

                   = P(A) + P(B) - P(A and B)

                   = 0.42 + 0.48 - 0.16

                   = 0.90 – 0.16 = 0.74

More from this chapter

All 43 →
37
Given P(A) = and P(B) = , find P(A or B) if A and B are mutually exclusive events.

38
(ii) P(not E and not F).

40
In Class XI of a school 40% of the students study Mathematics and 30% study Biology. 10% of the class study both Mathematics and Biology. If a student is selected at random from the class, find the probability that he will be studying Mathematics or Biology.

41
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 atleast one of them is 0.95. What is the probability of passing both?