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Why So Many People Get It Wrong
Our brains often focus on each event separately instead of looking at the final outcome.
People tend to think:
“He stole $100.”
Then they separately count:
“He bought $70 worth of products.”
Then again:
“He received $30.”
Without realizing it, they’re counting the same $100 bill twice.
The first time is when it was stolen.
The second time is when it returned to the register during the purchase.
Because the money comes back, it cannot also be counted as part of the final loss.
Think of It Another Way
Imagine the thief never bothered stealing the bill first.
Instead, suppose he somehow walked out of the store carrying:
- $70 worth of merchandise
- $30 in cash
The store would clearly be missing exactly $100.
The complicated story about stealing the bill simply distracts readers from seeing this simple result.
Why Riddles Like This Are So Popular
Logic puzzles have entertained people for generations because they reveal how our minds process information.
Many riddles aren’t testing mathematics.
They’re testing attention.
The numbers themselves are easy.
The real challenge lies in following the story without making hidden assumptions.
Our brains naturally look for shortcuts.
Sometimes those shortcuts work.
Other times they lead us to count the same object twice or overlook an important detail.
That’s exactly what happens in this puzzle.
Common Incorrect Answers
$200
This answer comes from adding every number mentioned in the story without realizing the $100 returns to the register.
$170
Some people count the original stolen money plus the merchandise but forget that the store recovered the cash.
$130
Others assume the store lost the merchandise plus the change plus part of the original theft.
Again, this overlooks the fact that the $100 bill ended up back inside the cash drawer.
Lessons Beyond the Puzzle
This simple riddle teaches a useful lesson that applies to many real-life situations.
Sometimes problems appear complicated simply because they’re presented in a confusing way.
Breaking the situation into small, logical steps often reveals that the solution is much simpler than expected.
Whether you’re solving puzzles, managing finances, making decisions, or evaluating information online, taking a moment to slow down and analyze each step can prevent costly mistakes.