Suppose a person who is developing a card game crowdfunds $40,000 and holds this as cash for future expenses. If this $40,000 comes from donors' checking accounts, by how much will the money supply fall if the reserve ratio is 10 percent?
A. The Money Supply will decrease by $___.
I've tried 4000, 40000, 36000, 44000, 400000, and everything else you can think of. Someone please help answer this!