# Chalkdust issue 11 puzzle hunt #5

Adam Townsend sets the fifth and final puzzle. Can you solve it?

The day is finally here: issue 11 is out now! To help you celebrate launch day in style, we’ve set a puzzle hunt: throughout the day, we are posting a series of puzzles. The answers to these puzzles form clues to the four-digit code for the door to let you into the Chalkdust issue 11 secret backstage lounge.

The fifth and final puzzle is set by Adam Townsend. You can see the puzzle below, or download it as a pdf.

Once you’ve solved this puzzle, head over to the Chalkdust issue 11 secret backstage lounge and unlock the door. See you inside!

Adam has been playing a game: he thinks of a secret word, tells you how many letters long it is, and lets you guess it. For each guess, he tells you how many letters in your guess are the correct letter in the correct position, and how many letters are the correct letter but in the wrong position.

For example, if Adam’s secret word is ‘GAME’, and you guess ‘ELMO’, he will tell you:

 Correct letter,correct position Correct letter,wrong position E L M O 1 1 ? ? ? ?

as the ‘M’ is the correct letter in the correct position, and the ‘E’ is the correct letter in the wrong position. If Adam’s secret word is ‘AABB’ and you guess ‘AAAB’, he will tell you:

 Correct letter,correct position Correct letter,wrong position A A A B 3 0 ? ? ? ?

as three letters are the correct letters in the correct position (AAAB), and there are no letters in the wrong positions as there is no third ‘A’ in Adam’s word. Adam doesn’t double count.

The secret words will spell out a clue to the code.

 Correct letter,correct position Correct letter,wrong position H A T 0 2 E T A 0 2 A R C 0 0 ? ? ?
 Correct letter,correct position Correct letter,wrong position M O D E 3 0 C U B E 2 0 ? ? ? ?
 Correct letter,correct position Correct letter,wrong position G R A D I E N T 1 3 M A N I F O L D 1 3 C O N V E R G E 3 0 N O T A T I O N 2 4 S E Q U E N C E 0 3 M U R D E R E D 0 0 ? ? ? ? ? ? ? ?
 Correct letter,correct position Correct letter,wrong position T A N 1 0 L A W 0 1 O D E 0 1 R O W 0 2 ? ? ?
 Correct letter,correct position Correct letter,wrong position R A N G E 1 1 S H E A R 0 2 I N N E R 2 2 O U T E R 1 0 ? ? ? ? ?

Adam is an assistant professor at Durham University, where he investigates weird, non-Newtonian fluids. If he’s not talking about the maths of chocolate fountains he is probably thinking about fonts, helping Professor Dirichlet answer your personal problems, and/or listening to BBC Radio 2.

• ### On the cover: VisualPDE.com

Ben Walker, Adam Townsend & Andrew Krause invite you to play with their fun online PDE visualiser
• ### My favourite LaTeX package

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• ### Page 3 model: Cows

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• ### Chalkdust issue 11 puzzle hunt #4

Humbug sets the fourth puzzle. Can you solve it?
• ### Chalkdust issue 11 puzzle hunt #3

David Sheard sets the third puzzle. Can you solve it?
• ### Chalkdust issue 11 puzzle hunt #2

TD Dang sets the second puzzle. Can you solve it?