A family of five goes out to dinner and spends $114.10. This includes a 20% tip. How much did the family's server receive for a tip?

Because it's included the $114.10 would be equal to 120%

You would divide by 12 to find 10%

Which is $9.51 and times this by 10 to find 100% which is $95.10

Then take $114.10 away from $95.10 and you get $19

The servers tip was $19