The Classic Register Riddle: Solving the Mystery of the Stolen $100 Bill
[ Step 1: Theft ] ──► Store loses $100 cash
[ Step 2: Purchase ] ──► Store gets the $100 cash back
──► Store gives away $70 in physical goods
──► Store gives away $30 in cash change
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[ Total Net Loss ] ──► $70 (goods) + $30 (cash) = $100 Total
🏆 The Definitive Answer
No matter how you look at the cash flowing in and out of the register drawer, the final calculation remains completely unchanged: The store lost exactly $100.
The simplest way to think about it from a broad perspective is to look entirely at what the thief walked away with at the very end of the day. He left the building holding $70 worth of merchandise and $30 in clean cash change. Because everything he used to acquire those items originally belonged to the store’s cash register, the total value of what he carried out the door matches exactly what the store lost.
💡 The Retailer’s Caveat: Cost vs. Retail Value
If you want to get technical from a business accounting perspective, a store owner might argue that the store lost slightly less than $100. Why? Because physical inventory is bought at wholesale prices. If the goods priced at $70 only cost the store $40 to purchase from a distributor, the store’s actual internal loss would be $40 (cost of goods) plus the $30 in cash change, totaling $70. However, in pure mathematical puzzle terms, the answer is always $100.
