MathProblem 12 Three men, a bell boy, and a motel room problem

Three men walk into a motel and ask for a room. The desk clerk says a room is 30 so each man pays 10 towards the cost. Later, the clerk realizes he made a mistake, that the room should have been 25. He calls the bell boy over and asks him to refund the other 5 to the three men. The bellboy, not wanting to mess with a lot of change dividing the 5 three ways, decides to lie about the price, refunding each man 1 and keeping the other 2 for himself. Ultimately each man paid 9 towards the room and the bellboy got 2, totaling 29. But the original charge was 30, where did the extra 1 go?

Solution

很经典的问题。实际上的付费为 \(25\)，而并非 \(30\)。每个人付了 \(9\)，所以总共为 \(27\)，而 bell boy 自己贪污了 \(2\)，所以很简单：

\[27-2=25 \]

没有多出来的 \(1\)