Why only $2?
1. Put $100 into your bank.
2. Take $10 out this leaves you $90
next day
3. Take $10 out. this leaves you $80
next day
4. Take $10 out. This leaves you $70
next day
5. Take $70 out. This leaves you 0.
According to your magical counts that would be $140 credit (90 + 80 + 70 - 100 = $140)
