There are 25 stations between Delhi and Chennai. How many second class tickets have to be printed, so that a passenger can travel from any station to any other station? Choose one
A) 802  B) 850  C) 852  D) 702  E) 722
The total number of stations = 27   From 27 stations we have to choose any two stations and the direction of travel (i.e., Delhi to Chennai is different from Chennai to Delhi) in 27P2 ways.   27P2= 27 * 26= 
<gadget id="calculator">27 * 26</gadget>
<output>702</output>
702   ANSWER: 702
<result>D</result>
There are 25 stations between Delhi and Chennai. How many second class tickets have to be printed, so that a passenger can travel from any station to any other station?