What were the 5 most popular puzzles?
These turned out to be the most popular puzzles of the year last year with the most entries, we finished on a high with the most popular puzzle being the final one of the year. This was probably due to the incredibly tight race for top spots in the school leaderboard.

All Answers 
Puzzle Number 
Name 
Topics 
Puzzle URL 
Solution URL 
1 
596 
42 
The Slight Changes Puzzle 
Number 
Puzzle 
Solution 
2 
459 
30 
The Padlock Puzzle 
Logic 
Puzzle 
Solution 
3 
452 
23 
The Handshake Puzzle 
Number, Permutations 
Puzzle 
Solution 
4 
439 
31 
The Minimum Notes Puzzle 
Number, Logic 
Puzzle 
Solution 
5 
397 
27 
The Really Cool Hat Puzzle 
Number 
Puzzle 
Solution 
What were the 5 most correctly answered puzzles?
Some of these puzzles were easy but others were just really impressively solved. The cipher puzzle is a bit of an outlier because unlike other puzzles you are unlikely to make a mistake in your calculations.
What were the 5 least correctly answered puzzles?
These were the toughest puzzles of the year, are you able to solve them?

% Correct 
Puzzle Number 
Name 
Topics 
Puzzle URL 
Solution URL 
1 
20% 
34 
The Seating Plan Puzzle 
Permutations 
Puzzle 
Solution 
2 
30% 
35 
The Straw Fist Puzzle 
Probability & Statistics, Permutations 
Puzzle 
Solution 
3 
33% 
24 
The Chess Piece Puzzle 
Permutations 
Puzzle 
Solution 
4 
33% 
28 
The Larger Latte Puzzle 
Geometry & Measure 
Puzzle 
Solution 
5 
37% 
38 
The Right Puzzle 
Geometry & Measure, Logic 
Puzzle 
Solution 
How was the difficulty distributed throughout the year?
Both the amount of answers submitted and the amount of correct answers submitted seem to have no pattern. However, the % correct seems to oscillate up and down, perhaps this is to do with the fact that nobody wants two really difficult puzzles back to back and so that was deliberately avoided.
How accurate are the difficulty ratings? All the puzzles receive a difficulty rating between 1 and 5 stars, 5 being the hardest. Below is an analysis of the % correct for each of the 42 puzzles. The box plots below show the distribution of the % correct for each puzzle. You can see that easier puzzles are generally more successfully answered but that there is overlap between the star ratings. You can also see that I have spent far too much time analysis how accurate the difficulty ratings are.
All Puzzle Data
Below is everything about how every puzzle in last year's competition was answered. However, they are all much better browsed through the puzzle library page.
Puzzle Number 
All Answers 
Correct Answers 
% Correct 
Name 
Topics 
Puzzle Hyperlink 
Solution Hyperlink 
12 
228 
93 
41% 
The ABCD Puzzle 
Number, Permutations 
Puzzle 
Solution 
13 
256 
96 
38% 
The Mouse & Cheese Puzzle 
Permutations 
Puzzle 
Solution 
14 
145 
122 
84% 
The Jack & Maddie Puzzle 
Algebra 
Puzzle 
Solution 
15 
277 
176 
64% 
Bob's Post Office Puzzle 
Ratio & Proportion, Geometry & Measure 
Puzzle 
Solution 
16 
276 
123 
45% 
The 110m Race Puzzle 
Ratio & Proportion, Geometry & Measure 
Puzzle 
Solution 
17 
325 
200 
62% 
The 6 Digits Puzzle 
Number, Logic 
Puzzle 
Solution 
18 
186 
127 
68% 
The Cube Displacement Puzzle 
Ratio & Proportion, Geometry & Measure 
Puzzle 
Solution 
19 
164 
81 
49% 
Selina's Tiles Puzzle 
Ratio & Proportion, Geometry & Measure 
Puzzle 
Solution 
20 
178 
162 
91% 
The Fruit Shop Puzzle 
Algebra 
Puzzle 
Solution 
21 
65 
54 
83% 
The Odd Addition Puzzle 
Number 
Puzzle 
Solution 
22 
245 
136 
56% 
The Two Teams Puzzle 
Permutations 
Puzzle 
Solution 
23 
452 
245 
54% 
The Handshake Puzzle 
Number, Permutations 
Puzzle 
Solution 
24 
279 
91 
33% 
The Chess Piece Puzzle 
Permutations 
Puzzle 
Solution 
25 
294 
177 
60% 
The Gummy Bears Puzzle 
Ratio & Proportion 
Puzzle 
Solution 
26 
187 
111 
59% 
The Symmetrical Go Puzzle 
Geometry & Measure 
Puzzle 
Solution 
27 
397 
320 
81% 
The Really Cool Hat Puzzle 
Number 
Puzzle 
Solution 
28 
336 
111 
33% 
The Larger Latte Puzzle 
Geometry & Measure 
Puzzle 
Solution 
29 
347 
332 
96% 
The Cipher Puzzle 

Puzzle 
Solution 
30 
459 
313 
68% 
The Padlock Puzzle 
Logic 
Puzzle 
Solution 
31 
439 
279 
64% 
The Minimum Notes Puzzle 
Number, Logic 
Puzzle 
Solution 
32 
228 
118 
52% 
The Light Bulb Puzzle 
Number 
Puzzle 
Solution 
33 
100 
82 
82% 
The Sliced Cube Puzzle 
Geometry & Measure, Number 
Puzzle 
Solution 
34 
104 
21 
20% 
The Seating Plan Puzzle 
Permutations 
Puzzle 
Solution 
35 
98 
29 
30% 
The Straw Fist Puzzle 
Probability & Statistics, Permutations 
Puzzle 
Solution 
36 
246 
138 
56% 
The Truncated Truncated Cube Puzzle 
Geometry & Measure 
Puzzle 
Solution 
37 
343 
270 
79% 
The Camel Racing Puzzle 
Logic 
Puzzle 
Solution 
38 
208 
76 
37% 
The Right Puzzle 
Geometry & Measure, Logic 
Puzzle 
Solution 
39 
329 
247 
75% 
The Octagon Puzzle 
Number 
Puzzle 
Solution 
40 
269 
123 
46% 
Selina's Tiling Job Puzzle 
Geometry & Measure 
Puzzle 
Solution 
41 
116 
69 
59% 
The Smallest Swap Puzzle 
Logic 
Puzzle 
Solution 
42 
596 
412 
69% 
The Slight Changes Puzzle 
Number 
Puzzle 
Solution 
