Marks obtained by 90 students of Class IX in a test are given below:
Marks | 0-20 | 20-40 | 40-60 | 60-80 | 80-100 |
No of students | 8 | 15 | 32 | 26 | 9 |
Out of these students one is chosen at random. Find the probability that the chosen student obtains
(i) less than 20% marks (ii) 80% of more marks
(iii) 60% or more marks
Total number of students : 90
Number of students who scored less than 20% : 8
Number of students who scored more than 80% : 9
Number of students who scored more than 60% : 35
Probability P() =
(i) Let P(20) be probability of students who scored less than 20%
P(20) =
(ii) Let P(80) be probability of students who scored more than 80%
P(80) =
(iii) Let P(60) be probability of students who scored more than 60%
P(60) =