Question

To know the opinion of the students about Mathematics, a survey of 200 students was conducted. The data is recorded in the following table:

Opinion:	Like	Dislike
Number of students:	135	65

 

Find the probability that a student chosen at random (i) likes Mathematics (ii) does not like it.

Answer 1

The total number of trials is 200.

Remember the empirical or experimental or observed frequency approach to probability.

If n be the total number of trials of an experiment and A is an event associated to it such that A happens in m-trials. Then the empirical probability of happening of event A is denoted by P (A)  and is given by

P (A) =`m/n`

(i) Let A be the event of liking mathematics.

The number of times A happens is 135.

Therefore, we have

P (A) =`135/200`

        = 0.675

(ii) Let B be the event of disliking mathematics.

The number of times B happens is 65.

Therefore, we have

P (B) =`65/200`

        = 0.325