In order to organize a 50-person tour group to carry out a "countryside folk custom" tour, the tour group stayed in a villager's house. There were three types of accommodation rooms: triple room, doub

In order to organize a 50-person tour group to carry out a "countryside folk custom" tour, the tour group stayed in a villager's house. There were three types of accommodation rooms: triple room, double room, and single room.

Solution: Suppose you live in a triple room, a double room, and a single room in x, y, and z rooms respectively, where x, y, and z are all natural numbers. The total accommodation fee is W yuan,

Then,

The solution is

∵x, y, z are all natural numbers

∴, or, or, or, or, or

p>

∴w=60x+60y+50z=-10z+1200,

∴w decreases with the increase of z,

∴When z=5 , that is, when x=15, y=0, z=5, the total cost of accommodation is the lowest.