Quick Sand Companions (example puzzle)
Waldemar the Elf has a job to do: he must collect all the Christmas wish lists from children who live in the Sahara Desert. Waldemar is fast: Starting in Timbuktu, he is able to complete the round trip and return to Timbuktu in six days. But he is also very small: An elf can only carry a maximum of four days’ worth of elf food.
Since the Sahara desert is very hot, Waldemar can't bring the Flying Reindeer to carry the food. Camels would be available in Timbuktu but they are too slow. There is no other choice than asking fellow elves to help him.
What is the minimum number of elves Waldemar needs to bring with him so he can complete the 6-day-trip and all elves return to Timbuktu healthy?
c) He can do it alone.
d) It's not possible at all.