Course 2, Question 10

[Anonymous]

Did anyone else think that this question was ridiculous? How can you answer it with the information that they gave?

[Macroman]

It's easy. Since the restaurant will not split the check, each diner will evenly split the cost of any items with all the other diners. This means that each diner will find that thier desert will cost them $1. Since each is willing to pay at least $3.50 for desert, all will order desert.

[cthawk]

does anyone know i professors from NEAS or Georgia State will post their answers sometime soon? They have in the past

[MathGuy]

I think Macroman's solution is a little unclear. We can elaborate a little more. The key is that the problem states that the check will be split evenly among "the colleagues" and not just those who eat dessert. Therefore, each colleague will pay 1/5th of the cost of each dessert. Thus, each customer will pay just $1 for their own dessert, and all five will order.

Suppose that customer A, who is only willing to pay 3.5 for his dessert, says "There's no way I'm buying dessert; it's too much money!". If all four of the others go ahead and get dessert, each of the diners would pay 4. A would then say to himself, "Self, if I also get dessert, it will only cost me an extra 1, which is well below my max of 3.5. So I should get dessert."

There is no way I would have gotten that in an exam situation.