In a certain province in France there are 13 cities. If a single road segment connects only two cities, how many road segments are required in order to connect the cities so that each city is connected to all other cities with a single road segment?  Pick one:
A) 76	B) 78	C) 75	D) 98	E) 72
1 city needs 12 roads to connect directly to the rest =&gt; 13 city needs 13*12 roads.   One road is counted twice =&gt; the number of road needed is 13*12/2= 
<gadget id="calculator">13*12/2</gadget>
<output>78</output>
78   Answer 78
<result>B</result>
In a certain province in France there are 13 cities. If a single road segment connects only two cities, how many road segments are required in order to connect the cities so that each city is connected to all other cities with a single road segment?