3 Utilities | 3 Houses puzzle?
A man has built three houses. Nearby there are gas water and electric plants. The man wishes to connect all three houses to each of the gas, water and electricity supplies.
Unfortunately the pipes and cables must not cross each other. How would you connect each of the 3 houses to each of the gas, water and electricity supplies
My concern is: If pipes and wire cannot cross with house and stations, then how to prove a solution does not exist by graph theory or combinatorics?
link to the original problem: http://puzzles.nigelcoldwell.co.uk/twentysix.htm