TOUGH MATH PROBLEM

Question

10 people are renting a house for spring break. The house is $590 to rent with a $310 down payment, so total $900. These 10 people pay $90 dollars each and expect to get $31 back from the deposit on the house. After these 10 people pay for the house a girl named Izzy comes and pays $8 cash to every person, she pays $80. How much does everyone get back from the deposit?

Answer 1

If Izzy is responsible for providing the expected deposit, then each of the ten people will still be expecting 31$ - 8$ (for the new combined expected deposit, multiply by 10). But if Izzy is a very generous random girl, then each of the ten people will still want 31$.

 

And we know how to subtract 8 from 31, don't we :)

 

Tutors, please feel free to review this argument.