C. 1329. King Sanislaus sends an envoy to a distant empire. In three days, a courier is sent back to the King's court with a message. It takes the courier two days to cover the same distance as the envoy takes three days to cover. With the answer, the courier returns to the envoy, and catches up with them exactly as they arrive at the destination. However, the emperor, who is a great friend of king Sanislaus, has been exiled in the meantime, so the entire envoy returns immediately, and this time they all travel at the speed of the courier. How many days elapse between the envoy starting their journey and returning to the court?
This problem is for grade 1 - 10 students only.
Deadline expired on 10 February 2016.