Y by Adventure10, Mango247
There are some cities in a country; one of them is the capital. For any two cities
and
there is a direct flight from
to
and a direct flight from
to
, both having the same price. Suppose that all round trips with exactly one landing in every city have the same total cost. Prove that all round trips that miss the capital and with exactly one landing in every remaining city cost the same.





