The table given below shows the marks obtained by 30 students in a test.


Marks (class interval)



Number of students (frequency)



1-10



7



11-20



10



21-30



6



31-40



4



40-50



3



Out of these students, one is chosen at random. What is the probability that his marks lie in the interval 21-30?

Total number of Students: 30


Number of Students having marks in the range 21-30: 6


Probability P() =


1.Let P(S) be probability of selecting a student having marks in the range 21-30


P (S) =


P (S) = = 0.2


10