Question

If 4 of 12 scooterists do not carry driving licence, what is the probability that a traffic inspector who randomly selects 4 scooterists will catch (1) 1 for not carrying driving licence. (2) at least 2 for not carrying driving licence.

Answer 1

(i) 32/81 (ii) 11/27

Step-by-step explanation:

Let p be the probability that a scooterist does not have a driving licence.

Then p = not carrying licence/total number of scooterists

           = 4/12

           =1/3

        q = 1-p = 2/3 and n = 4

(i) Probabily of the police catching one scooterist not having driving licence is explained in picture 1.

           = 32/81

(ii) Probabily of the police catching at least two scooterists not having driving licence is explained in picture 2.

           = 11/27