[" There are "12" stations on a certain railway line.How many "],[" different kinds of tickets of class II must be printed in order "],[" that a passenger may go from any one station to any other? "]

There are 13 stations on a certain railway line.How many kinds of different single third class tickets have to be printed in order that it may be possible to travel from any station to any other?

There are 15 stations on a certain railway line. How many different types of tickets must be printed so that a passenger can travel from any station to another in that line?

There are 50 stations on a railway line . How many different kinds of single 1st class tickets must be printed so as to enable a passenger to go from one station to another

There are 50 stations on a railway line. The number of different kinds of single 2nd class tickets must be printed so as to enable a passenger to go from one station to another station is

There are 50 stations on a railway line.The number of different kinds of single 2 nd class tickets must be printed so as to enable a passenger to travel from one station to another station is:

There are 17 stations from Howrah to Bandel on the railway line . How many kinds of different single third class tickets must be printed so as to enable a passenger to travel from one station to another?

If there are 25 railway stations on a railway line, how many types of single second class tickets must be printed, so as to enable a passenger to travel from one station to another.

If there are 30 Railway stations on a Railway line, how many number of single second class tickets must be printed so as to enable a passenger to travel from one station to another.