Squigly Squigly's Brain Teasers

Question:

If 7 is transformed into 13 and 11 is changed to 21 then what does 16 become?

Answer:

31, because I multiplied the number by 2 and subtracted one.

Try another Brain Teaser:

How was mail delivered in the days of the Old West?

We have lots more puzzles to provide fun for your brain. Have fun solving these quiz questions. Choose from the following brain games: