## November 2017 Fiendish Function

The Fiendish Function posed during November 2017 had the following sample guesses and replies:

- 1
- 9
- 2
- 16
- 3
- 21
- 4
- 24
- 5
- 25
- 10
- 0

The rule was: "Minus one times the number squared plus ten times the number".

Suppose the guess was 13:

- Take -1 times the number squared, giving -169
- Add 10 times the number, giving -39

So the result is -39.

## Earlier answers

Here are the answers to the Fiendish Functions posted in earlier months: