Two sections of class 9 having 27 students in each section appeared for an exam.The marks obtained by them are 46,31,74,68,42,54,14,61,48,37,26,8,64,57,93,72,53,59,38,16,88,56,46,66,45,61,54,27,27,44,63,57,43, 81,64,36,49,50,76,38,47,77,62,53,40,71,60,45,42,34,46,40,59,42 One student is selected at random .find the probability that selected student is 1. Having marks more than 49 2. Having marks between 39 and 99
Answers
Total no.of students are 54
Probability = 27/54 = 9/18 = 1/2 .
(ii) No.of students having marks between 39 and 99 are 42
Total no.of students are 54
Probability = 42/54 = 14/18 = 7/9 .
Given,
Two sections of class 9 having 27 students in each section appeared for an exam.The marks obtained by them are 46,31,74,68,42,54,14,61,48,37,26,8,64,57,93,72,53,59,38,16,88,56,46,66,45,61,54,27,27,44,63,57,43, 81,64,36,49,50,76,38,47,77,62,53,40,71,60,45,42,34,46,40,59,42
To Find,
One student is selected at random .find the probability that selected student is
1. Having marks more than 49
2. Having marks between 39 and 99
Solution,
(1) No.of students having more than 49 marks = 27
Total no.of students are 54
Probability = 27/54 = 9/18 = 1/2
(2) No.of students having marks between 39 and 99 = 42
Total no.of students are 54
Probability = 42/54 = 14/18 = 7/9
Hence, (i) the probability that the selected student is having marks more than 49 is 1/2, and (ii) the probability that the selected student is having marks between 39 and 99 is 7/9.