The Classic Register Riddle: Solving the Mystery of the Stolen $100 Bill
đź§ Breaking Down the Timeline Step-by-Step
To find the correct answer without getting tripped up by the shifting cash, it helps to treat the riddle as two entirely separate events.
Event 1: The Theft
The man walks up to the register and surreptitiously removes a crisp $100 bill.
- The Register Balance: –$100
- The Thief’s Pocket: +$100
- Net Loss at this moment: The store is down exactly $100.
Event 2: The Purchase
The man returns to the counter acting like a legitimate customer to purchase $70 worth of store merchandise. He hands over the stolen $100 bill to pay for it.
- The Cash Inflow: The thief hands the cashier a $100 bill. The register gets its stolen $100 bill back (the cash balance returns to 0).
- The Goods Outflow: The cashier hands the man $70 worth of physical goods (the store is now down $70 in inventory).
- The Change Outflow: The cashier hands the man $30 in cash change from the drawer (the store is now down an additional $30 in cash).
