You will be faced with a model rail layout, on which there will be a locomotive and eight brightly coloured wagons.
The wagons will be matched to eight brightly coloured table tennis balls, held in a sealed bag.
The bag will be shaken and handed to the team to draw out 5 balls and place them on the stand in the order they are drawn from the bag.
The bad news is the team then has to shunt the wagons into the correct order!
The permutations are endless (over 4,000 we are told); at the end of the challenge.
