Answer to Question #269442 in Statistics and Probability for sumu

Question

i) Kishan is a sales executive who has to make visits to Colombo, Kandy, Galle,

Gampaha, Panadura and Negombo. He has to visit each city once only and always

takes the unique shortest route between any two cities.

Kishan's manager calls and now tells him he has to start his journey in Galle

and must visit four cities in total. How many possible routes are there for

Kishan in this case? ( 4 marks)

f. If Kishan was to pick a route for the shortened four city journey at random,

what is the probability that the route he selected would be one starting from

Galle?

Answer 1

i) The order does not matter

$$C(5, 3)=\dbinom{5}{3}=\dfrac{5!}{3!(5-3)!}=\dfrac{5(4)}{1(2)}=10$$

f.

$$p=\dfrac{1}{6}$$