February 2014
Problem of the Month

Tipping Problem

Mr. P was telling a friend about the terrible service that he received at the Walrus Restaurant in Bismarck, North Dakota.   "The food was great but the server was extremely rude, so I only tipped her 14%.   Instead of giving her $10.00, I only gave her $6.00."   What percent would Mr. P have tipped her if he had given her $10?

Solution to the Problem:

The answer is 23.3%.

Let x = the cost of the dinner.
Then .14x = 6.00
So, x = $42.86 (the cost of the dinner)
Then the percent Mr. P normally would have tipped = 10.00 / 42.86 = 23.33%.

You could have also set up a proportion to solve this problem:
14 / 6 = x / 10
x = 23.33%

Correctly solved by:

1. James Alarie	Flint, Michigan
2. Shaylynn Martin	Mountain View High School, Mountain View, Wyoming
3. Riley Dolezal	Mountain View High School, Mountain View, Wyoming
4. Isaac Kampman	Mountain View High School, Mountain View, Wyoming
5. Maria Lugo	John Paul II Catholic School, Tallahassee, Florida
6. Erin H. and Danielle S.	John Paul II Catholic School, Tallahassee, Florida
7. Philip Regalado	John Paul II Catholic School, Tallahassee, Florida
8. Maria	----------

Send any comments or questions to: David Pleacher