There are 15 stations between Hyderabad and Bangalore. How many second class tickets have to be printed, so that a passenger can travel from any station to any other station?  Options.
A) 272
B) 167
C) 157
D) 352
E) 380

Rationale: "the total number of stations = 17 from 17 stations we have to choose any two stations and the direction of travel ( i . e . , hyderabad to bangalore is different from bangalore to hyderabad ) in 17 p ₂ ways . 17 p ₂ = 17 * 16 = 272 . answer : a"
Answer: A