Question
Priya, Mai, and Lin went to a cafe on a weekend. Their shared bill came to $25. Each student gave the server a $10 bill. The server took this $30 and brought back five $1 bills in change. Each student took $1 back, leaving the rest, $2, as a tip for the server.
As she walked away from the cafe, Lin thought, “Wait—this doesn’t make sense. Since I put in $10 and got $1 back, I wound up paying $9. So did Mai and Priya. Together, we paid $27. Then we left a $2 tip. That makes $29 total. And yet we originally gave the waiter $30. Where did the extra dollar go?”
Think about the situation and about Lin’s question. Do you agree that the numbers didn’t add up properly? Explain your reasoning.
As she walked away from the cafe, Lin thought, “Wait—this doesn’t make sense. Since I put in $10 and got $1 back, I wound up paying $9. So did Mai and Priya. Together, we paid $27. Then we left a $2 tip. That makes $29 total. And yet we originally gave the waiter $30. Where did the extra dollar go?”
Think about the situation and about Lin’s question. Do you agree that the numbers didn’t add up properly? Explain your reasoning.
Answers
oobleck
this is an old old illusion.
There is no missing dollar.
Since they each got a dollar back, they only spent $27 altogether.
The bill was $25, and the waiter got $2.
There is no missing dollar.
Since they each got a dollar back, they only spent $27 altogether.
The bill was $25, and the waiter got $2.