I got this one from my father. You are currently in one of two towns separated by a desert. You need to cross the desert to get to the other town. It takes 6 days to cross the desert, but a single person can carry only 4 days worth of food supply. You can hire porters to help you carry your food supply, but naturally you want to minimize the costs as much as possible. What would be the plan that will enable you to cross the desert while paying for the minimum possible number of porter days?

I’ll post the solution next week.