There are 28 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?
Choose the most appropriate option:
A) 156
B) 167
C) 870
D) 352
E) 380
The total number of stations = 30   From 30 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 3⁰P₂ ways.   30P₂ = 30 * 29= 
<gadget id="calculator">30 * 29</gadget>
<output>870</output>
870.   Answer: 870
<result>C</result>
There are 28 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?