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Christmas (2025) is over

 2026-02-08 
Welcome to 2026 everyone! It's time to reveal the answers to the Advent Calendar puzzles and announce the winners. But first, some good news: with your help, Santa was able to order a new sleigh and Christmas was saved!
Now that the competition is over, the questions and all the answers can be found at mscroggs.co.uk/puzzles/advent2025. Before announcing the winners, I'm going to go through some of my favourite puzzles from the calendar and a couple of other interesting bits and pieces.

Highlights

My first highlight is the puzzle from 9 December. I like this puzzle, and enjoy how it looks like a complicated counting puzzle at first, but there's a much simpler method available...

9 December

In a 3 by 5 grid of squares, if a line is drawn from the bottom left corner to the top right corner, it will pass through 7 squares:
In a 251 by 272 grid of squares, how many squares will a line drawn from the bottom left corner to the top right corner pass through?

Show answer & extension


My next highlight is the puzzle on 17 December. This is a highlight because I just really like the puzzle.

17 December

A sequence of zeros and ones can be reduced by writing a 0 or 1 under each pair of numbers: 1 is written if the numbers are the same, 0 is written if they are not. This process can be repeated until there is a single number. For example, if we start with the sequence 1, 1, 1, 0, 1 (of length 5), we get:
1
1
1
0
1
1
1
0
0
1
0
1
0
0
1
The final digit is a 1.
How many sequences of zeros and ones of length 10 are there that when reduced lead to the final digit being a 1?

Show answer



My final highlight is the puzzle from 18 December, as I always enjoy a surprise Fibonacci.

18 December

There are 5 different ways to make a set of numbers between 1 and 5 such that the smallest number in the set is equal to the number of numbers in the set. These 5 sets are: {1}, {2, 3}, {2, 4}, {2, 5} and {3, 4, 5}.
How many ways are there to make a set of numbers between 1 and 14 such that the smallest number in the set is equal to the number of numbers in the set?

Show answer

Hardest and easiest puzzles

Once you've entered 24 answers, the calendar checks these and tells you how many are correct. I logged the answers that were sent for checking and have looked at these to see which puzzles were the most and least commonly incorrect. The bar chart below shows the total number of incorrect attempts at each question.
It looks like the hardest puzzles were on 21, 15 and 14 December; and the easiest puzzles were on 3, 10, 5 and 8 December.

Ordering the sleigh

To finish the Advent calendar, you were tasked with ordering the correct parts for a new sleigh. The answers to all the puzzles were required to be certain of which combination of parts was needed, but it was possible to reduce the number of options This graph shows how many people successfully ordered a sleigh on each day:

The winners

And finally (and maybe most importantly), on to the winners: 242 people managed to order a slieigh. That's a record high number!
From the correct answers, the following 10 winners were selected:
  • Adrienne Hestenes
  • Blake Segler
  • Johannes C. Huber
  • Matthew Harding
  • Mr J Winfield
  • Pamela Docherty
  • Pete Chare
  • Steve Blay
  • Tim Dufton
  • Vinny R
Congratulations! Your prizes will be on their way shortly.
The prizes this year include 2025 Advent calendar T-shirts. If you didn't win one, but would like one of these, I've made them available to buy at merch.mscroggs.co.uk alongside the T-shirts from previous years.
Additionally, well done to 100118220919SantaSixSeven9, A Hall, Aaron Kunze, Aisha Arroyo, Alan Buck, Alan Shotkin, alek2ander, Alex Bolton, Alex Slaughter, Allan Taylor, Anastasia P, Anastasiia, Andrea Chlebikova, Andrew Brady, Andrew Fermor, Andrew Roy, Andrew T, Andrew Thomson, Andy Ennaco, Artie Smith, Ashley Jarvis, B Witt, Becky Russell, beeplusdub, Ben Baker, Ben Boxall, Ben J, Ben Reiniger, Ben Semanko, Ben Tozer, Ben Weiss, Bill, Bill Russ, Bob B, Brian Wellington, Carmen, Cathy Hooper, Chad Smith, Chloe, Chris Dettmar, Chris Eagle, Chris Hazell, Chris Hellings, Christopher Adams, Clint Cabrera, Colin Beveridge , Colin Brockley, Connie, Cool Beans, Corbin Groothuis, Cristian Sbârciog, dajedrek, Dan Colestock, Dan May, Dan Whitman, Daniel, Daniel Low, Danny, Dave, Dave Budd, David, David Ault, David Berardo, David Carey, David Fox, David Kendel, Deborah Tayler, Dhruv Pisharody, Donagh, Donald Anderson, Dylan, Dylan Madisetti, Echo231, Elijah Kuhn, Elizabeth Madisetti, Ellie Winters, Elytre, Emily Troyer, Eoin Davey, epsilon, Eric Kolbusz, Erick Lee, Evan and Dana, Evan Denney, Evan S, Ewan Beetham, F Z, Fabien Friedli, Fionn Woodcock, Frank Kasell, Fred Verheul, Gabriella , Gareth McCaughan, Gary M. Gerken, Gary Male, Gert-Jan, Gregory Wheeler, Guillermo Heras Prieto, H.Hung, Hannah Harris, Heerpal, Helen, Herschel, Holly Carnes, Håkon Balteskard, IanAllenBird, Iris Lasthofer, Isabel Turner, Ivan Andrus, Jacob, Jamas Enright, James Chapman, James Dolengewicz, James Swenson, Jan Zemba, Jay Winter, JDev, Jean-Noël Monette, Jen Sparks, Jessica Marsh, Joe Gage, Johan, Jon Palin, Jonathan Chaffer, Jonathan Thiele, Jorge del Castillo Tierz, Josh Hernandez, Judith W, Kat, Kat Yates, Katerina Stergiopoulou, Katie Steckles, Keerthana, Kevin Docherty, Kirsty Fish, Kristen Koenigs, Larry Goddard, lastrun, Lazar Ilic, LDufton, Leif Cooper, Lewis Dyer, Lisa Stambaugh, Lise Andreasen, Lizzie McLean, Lorelei, Louis, Lucas Bowman, Magnus Eklund, Mair A-W, Marc G., Marco van der Park, Mark Lydon, Mark Stambaugh, Martin Harris, María Jesús Rapanague, mathmandan, Matthew Courtney, Matthew Schulz, Max, Maya, Michael, Mihai Zsisku, Mike Graczyk, Millie, Mimi Manning, Mister Ron, Monopoler, Nazneen Molu, Neil Bastian, Nick C, Nick Keith, Nikos I., Noah Molder, Noah O, Oli M, Olov, Pablo Carballeira, Peter Krol, Peter Rowlett, Pierce R, Pollyanna, Pythialouise, Rachel Sheridan, RADina, Rashi, Ray Arndorfer, Richard O, Rob Reynolds, Robert, Robert Allwright, Roger, Roni, Ronno, Rosamund, Rosie Paterson, Sadie Robinson, Sam Dreilinger, Sam Peterson, Sam123guy, Samuel Wilson , Scio Durango, Scott, Sean Henderson, Seth Cohen, Shannon Stranahan, Shivanshi, Simon English, sjlxndr, stephen kirkham, Stephen Royle, Tamas Toth, Tarka Burrell, Tehnuka, The Connors of York, Thomas O'Neill, Tim B, Timothy Conlan, Tina Furer, Tino, Tony Mann, Travis, tripleboleo, UsrBinPRL, Valentin VĂLCIU, Victor MIller, Vinayak, Will Bayliff, Willem, Yasha, and zook who all also completed the Advent calendar but were too unlucky to win prizes this time or chose to not enter the prize draw.
See you all next December, when the Advent calendar will return.
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Comments

Comments in green were written by me. Comments in blue were not written by me.
Yes I did puzzle 9 by working out how many would be coloured in each row or something, and only realised that there was a simpler way when I saw the final formula. Cheers pal
Alex Bolton
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