Monthly Brainteaser and November’s answerTuesday, December 6th, 2011
Last month you were given this problem:
A large army of infantry was marching along roads through a country at a steady 3mph. The column was 9 miles long. A despatch rider at the rear of the column was sent with an urgent message to the commander at the front of the column. He delivered the message and immediately turned round and returned to the rear of the column, which by now had moved forward. He travelled throughout at a steady 36 mph. Bearing in mind that neither he nor the army paused and the place on the map from which he started from was no longer the place to which he returned, how far did he travel on the two legs of his journey?
This is a case of information overload – you need not use all the statistics given. The column was 9 miles long. Since he travelled the length of it twice, he travelled 18 miles in total.
Now this month, one for Christmas afternoon:
A baron builds a castle on a square island and surrounds the island with a moat that in turn forms a square. The moat is 10 metres wide. An enemy decides to attack the castle by crossing the moat on long strengthened planks. Unfortunately when they arrive they find that the planks are half a metre too short. Is there some way they can still get across the moat and onto the island or must they return home in disgrace?