in a recent survey, the following data were obtained in response to the question

Question

CLASS	YES	NO	NO OPINION	TOTAL
FRESHMEN	15	8	5	28
SOPHOMORES	24	4	2	30
TOTAL	39	12	7	58

IF A STUDENT IS SELECTED AT Random, find the probability that the student

(i) has no opinion

(ii) is a freshman or is against the issue

(iii) is a sophomores and favours the issue

(iv) is neither a freshman nor favours the issue

 

Answer 1

7 students out of 58 have no opinion, so probability=7/58=12.07%.

Probability of being a freshman is 28/58 and probability of a random student answering no is 7/58, so the chances of one or the other is 28/58+7/58=35/58=60.34%.

24/58=41.38% is the probability of a sophomore favouring the issue.

Since a non-freshman means a sophomore and not favouring the issue means no or no opinion, the probability is 6/58=10.34%.