The marks obtained by 90 students of a school in Mathematics out of 100 are given as under:


Marks



0-20



20-30



30-40



40-50



50-60



60-70



70 and above



No of students



7



8



12



25



19



10



9



From these students, a students is chosen at random.


What is the probability that the chosen student


(i) gets 20% or less marks?


(ii) gets 60% or more marks?

Total number of students : 90


Number of students who scored less than 20% : 7


Number of students who scored more than 60% : 19


Probability P() =


(i) Let P(20) be probability of students who scored less than 20%


P(20) = =


(ii) Let P(60) be probability of students who scored more than 60%


P(60) = =


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