Aseemingly straightforward math brainteaser has suddenly gone viral in today’s internet environment, when content can spread quickly. The task at hand asks participants to estimate the amount of money a business lost following a theft of a $100 bill by a crook who then made a transaction. There has been a lot of discussion about this $100 puzzle online, especially among puzzle fans.

The user account Out of Context Human Race posted the puzzle on X, formerly known as Twitter. The scenario it depicts is a man robbing a store of $100 in cash, using it to purchase $70 worth of products and making $30 in change. The next question in the puzzle is, “How much money did the store lose?”

This brainteaser received a barrage of responses when it went viral online, many of them boldly asserting that their answer was correct. While some claimed that the store only lost $100, others estimated that the loss was actually $130 after accounting for the stolen $100 as well as the $30 that was handed as change. Some even went so far as to say that the profit margins on the products sold would determine the store’s overall loss.

Understanding the scenario’s precise circumstances is essential to solving this puzzle. At first glance, it could seem obvious to determine that the theft cost the store $100. But the reality is more complicated. The store technically recovered the $100 when the burglar used it to make a purchase. However, the store suffered a $30 net cash loss when they gave the burglar $30 in change.