Question

The marks obtained by a student in different subjects in an exam are given below.

$\begin{array}{cc}\text{Subject}& \text{Marks}\\ \text{English}& 77\\ \text{Hindi}& 90\\ \text{Maths}& 70\\ \text{Physics}& 86\\ \text{Chemistry}& 85\\ \text{Biology}& 97\\ \text{Computer Sci.}& 59\\ \text{History}& 62\\ \text{Geography}& 100\\ \text{Moral Sci.}& 75\end{array}$

Find the probability that in an exam, she will score
(i)100
(ii)80 or more
(iii) less than 60. [4 MARKS]

Answer 1

Concept:1Mark
Solution:1Mark each

Total number of exams = 10.
Number of exams in which the student scored a hundred = 1.
Probability of scoring hundred = $\frac{1}{10}$ = 0.1.
Number of exams in which she scored 80 or more = 5.
Probability of scoring 80 or more =$\frac{5}{10}$ = 0.5.
Number of exams in which she scored less than 60 = 1.
Probability of scoring less than 60 =$\frac{1}{10}$ =0.1.