There is a desert which can be crossed only by walking and this takes six days. The explorers of the desert can carry at most four days' water and food. If they want, they can take helpers with them. Each helper can also carry at most four days' supply. What is the minimum number of helpers that an explorer need to cross the desert?
"If the explorer takes one helper with him, after two days both are left with two days' food and water. Then the explorer could take the helper's food and water and cross the desert easily. But the helper would die in the desert."- This kind of cruel solution is not acceptable. No helpers should starve at any point.
Taken from the book Neurone Abaro Onuronon by Muhammad Zafar Iqbal.