Click through each step to see how the money moves around and exactly where the confusion happens!
Three friends go to a restaurant and order a meal that costs $30. They each pay $10. Later, the restaurant realizes they overcharged - the meal should have cost only $25. The restaurant gives $5 to the waiter to return to the customers. However, the waiter decides to keep $2 as a tip and gives only $3 back to the friends ($1 each).
Now each friend has paid $9 (since they got $1 back). So they paid $9 Ã 3 = $27 in total. The waiter kept $2. That's $27 + $2 = $29... but they originally paid $30. Where did the missing $1 go?
What's the fundamental mistake in the "missing dollar" reasoning?
ðĄ Click an answer, then go through the steps to see if you're right!
Friends paid: $9 Ã 3 = $27
Plus waiter's tip: $27 + $2 = $29
But they started with $30... Where's the missing $1?
The error is in the final calculation! We shouldn't add the $2 tip to the $27.
The $2 tip is part of the $27 the friends paid, not additional to it!
$27 (friends paid) = $25 (meal) + $2 (tip)
Challenge your friends and family with this classic puzzle!
ðĄ Fun Fact: This puzzle demonstrates how our intuition about money can lead us astray. It's a great example of why careful accounting and mathematical thinking are so important!
People mistakenly add the $2 because they're probably mixing two different viewpoints:
From the friends' perspective: They paid out $27 total
From the waiter's perspective: The waiter received $2
When people see "friends paid $27" and "waiter has $2," they instinctively think these are two separate outflows that should add up to the original $30.
They're essentially asking: "Where did the $30 go?" and incorrectly thinking it went to two places: $27 to "somewhere" plus $2 to the waiter.
The mistake is not recognizing that the $2 the waiter has came from the $27 the friends paid - it's not additional to it.
They should be thinking: "The $27 the friends paid was split between the restaurant ($25) and waiter ($2)."