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InterviewSolution
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Following frequency distribution gives the weights of 40 students of a class . A student from the class is chosen at random . What is the probability that the weight of the chosen student is (i) at most 60 kg (ii) at least 56 kg (iii) not more than 50 kg ? |
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Answer» Total number of students = 40. (i) Let `E_(1)` be the event of choosing a student whose weight is at most 50 kg . Then , P(choosing a student whose weight is at most 60 kg) = `P(E_(1))` `= ("number of students whose weight is 60 kg or less")/("total number of students")` `= (10 + 6 + 14 + 4 + 1 + 1)/(40) = (36)/(40) = (9)/(10)`. (ii) Let `E_(2)` be the event of choosing a student whose weight is at least 56 kg . then , P(choosing a student whose weight is at least 56 kg) `= P(E_(2))` =`("number of students whose weight is 56 kg or more")/("total number of students")` `= (1 + 2 + 1+ 1)/(40) = (5)/(40) = (1)/(8)` . (iii) Let `E_(3)` be the event of choosing a student whose weight is not more than 50 kg . then , P(choosing a student whose weight is not more than 50 kg) `= P(E_(3))` `= ("number of students whose weight is 50 kg or less")/("total number of students")` `= (10 + 6 + 14+ 4)/(40) = (34)/(40) = (17)/(20)`. |
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