In a certain province in France there are 11 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?  Choose the correct choice from the following options.
A) 55  B) 105  C) 330  D) 143  E) 156
1 city needs 10 roads to connect directly to the rest =&gt; 11 city needs 11*10 roads.   One road is counted twice =&gt; the number of road needed is 11*10/2= 
<gadget id="calculator">11*10/2</gadget>
<output>55</output>
55   55nswer 55
<result>A</result>
In a certain province in France there are 11 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?