Gas Electricity Water Puzzle

How do you connect mr angry mr beastly and mr cross to gas water and electricity without.

Gas electricity water puzzle.

Suppose there are three cottages on a plane or sphere and each needs to be connected to the water gas and electricity companies. The three cottages problem or sometimes water gas and electricity can be stated as follows. In a suburb three new houses all have to be connected to a gas red water blue and electricity green supply. The classical mathematical puzzle known as the three utilities problem.

A man has built three houses. 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. Each year we receive an extraordinary number of letters regarding a classic route problem called water gas and electricity.

Nearby there are gas water and electric plants. Connecting gas water electric to three houses. All houses should get their own gas water and electricity connection. Furthermore no connections may cross each other.

This problem is perhaps the perfect introduction to graph theory.