Following frequency distribution gives the weights of the students of a class.
Weight(in kg)31−3536−4041−4546−5051−5556−6061−6566−7071−75Number of students36139117421
Find the probability of
(i) choosing a student at random whose weight is atmost 40kg
(ii) choosing a student at random whose weight is greater than 40kg but less than 60kg
(iii) choosing a student at random whose weight is greater than 60kg [3 MARKS]
Solution: [1 Mark each]
Total number of students = 56
Probability of picking a student whose weight is less than or equal to 40 = (3+6)56 = 9/56
Probability of picking a student whose weight is greater than 40 and not greater than 60 = (13+9+11+7)56 = 40/56 = 5/7
Probability of picking a student whose weight is greater than 60 = (4+2+1)56 = 7/56 = 1/8.