Did you solve it? The deductive decade – ten years of Monday puzzles

TruthLens AI Suggested Headline:

"Celebrating Ten Years of Monday Puzzles with Classic Challenges and Solutions"

Did you solve it? The deductive decade – ten years of Monday puzzles analysis cover image The Guardian 9.7
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Original Article Source: https://www.theguardian.com/science/2025/jun/09/did-you-solve-it-the-deductive-decade-ten-years-of-monday-puzzzles
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AI Analysis Average Score: 9.7
These scores (0-10 scale) are generated by Truthlens AI's analysis, assessing the article's objectivity, accuracy, and transparency. Higher scores indicate better alignment with journalistic standards. Hover over chart points for metric details.

TruthLens AI Summary

In celebration of a decade of engaging puzzles, the column revisits ten selected challenges from its archives, providing both the puzzles and their solutions. Each puzzle is designed to test deductive reasoning and critical thinking, showcasing a variety of scenarios. For instance, the first puzzle involves three friends playing ping pong, with the task of determining who lost the second game based on the number of games played by each participant. Another puzzle, 'Tricky trams,' explains the engineering behind the zigzag pattern of tram overhead cables, highlighting the need for even wear on the pantograph to prevent damage. Other puzzles challenge readers to find a cat behind one of several doors, deduce the properties of a ten-digit number, and unravel the logic behind a seemingly contradictory statement involving categories of answers. Each puzzle invites readers to engage deeply with the reasoning required to arrive at the solutions.

Further puzzles delve into visual and mathematical challenges, such as explaining a reflection of a lion cub and proving the existence of a triangle with an area larger than Earth's surface despite its minuscule height. The column encourages readers to think creatively, as seen in the card guessing dilemma where the optimal question does not impact the odds of guessing correctly. The article concludes with an invitation for readers to suggest new puzzles, emphasizing the ongoing quest for intellectual stimulation. Overall, these puzzles serve not just as entertainment but also as a means to sharpen reasoning skills and engage with complex concepts, reflecting the column's commitment to fostering a love for problem-solving over the past ten years.

TruthLens AI Analysis

The article presents a nostalgic reflection on ten years of Monday puzzles, inviting readers to engage with a selection of previously published logic puzzles. This celebration of intellectual challenge serves not only as entertainment but also as a means of fostering community engagement around problem-solving.

Purpose of the Article

The primary intention behind this article is to commemorate a decade of puzzles, encouraging readers to revisit and solve these brain teasers. By providing the original puzzles along with their solutions, the author aims to rekindle interest among long-time followers and attract new participants. This retrospective approach emphasizes the value of critical thinking and the enjoyment derived from solving puzzles.

Public Perception

The article seeks to cultivate a sense of community and shared experience among puzzle enthusiasts. By inviting readers to engage with the material actively, it fosters an environment where intellectual curiosity is celebrated. This can lead to a positive perception of the publication as a source of both entertainment and mental stimulation.

Potential Omissions

There does not appear to be any obvious attempt to conceal information or manipulate public opinion in this article. Its straightforward approach to presenting puzzles supports transparency rather than obscuring underlying issues. The focus on puzzles and solutions does not lend itself to deeper political or economic implications, making it less likely to serve as a cover for other news.

Authenticity and Reliability

This news piece is grounded in the reality of past puzzles and their solutions. The puzzles themselves are well-known logical challenges that have been part of the column for a decade, thus reinforcing the article's credibility. Readers are likely to find the content trustworthy, as it provides a clear purpose without any misleading narratives.

Societal Impact

While the article primarily serves as a form of entertainment, its emphasis on problem-solving may inspire readers to engage more actively in critical thinking. This could foster a broader appreciation for intellectual challenges, potentially influencing educational approaches or community activities centered around puzzles.

Target Audience

The content is likely to resonate with a diverse audience, particularly those who enjoy puzzles, logical reasoning, and community-oriented activities. It appeals to individuals who appreciate mental challenges and may also attract families looking for engaging activities.

Market Influence

Given the nature of the article, it is unlikely to have a direct impact on stock markets or global economics. However, it could indirectly influence sectors related to education, publishing, or entertainment that focus on puzzles and intellectual engagement.

Geopolitical Relevance

There are no immediate geopolitical implications associated with the article. Its focus on puzzles does not intersect with current global issues or power dynamics, suggesting it is intended purely for entertainment rather than commentary on international affairs.

AI Involvement

It is possible that AI might have been used in the generation of the puzzles or in the formatting of the article, but the content appears to be straightforward and traditionally constructed. If AI was employed, it likely contributed to enhancing readability or organizing the material effectively.

In conclusion, this article stands as a celebration of intellectual engagement through puzzles, aiming to encourage participation and foster a sense of community among readers. The focus on logical challenges and the nostalgic element enrich its value, making it a reliable source for puzzle enthusiasts.

Unanalyzed Article Content

Source URL: https://www.theguardian.com/science/2025/jun/09/did-you-solve-it-the-deductive-decade-ten-years-of-monday-puzzzles

To celebrate ten years of this column, this morning I selected ten puzzles from the Monday Puzzle archives. Here they are again with solutions. Click on the solutions to be taken to the original columns, which have full explanations.

  1. Bat and ball

Three friends (A, B and C) are playing ping pong. They play the usual way: the winner stays on, and the loser waits their turn again. At the end of the day, they summarise the number of games that each of them played:

A played 10

B played 15

C played 17.

Who lost the second game?

SolutionA

  1. Tricky trams

Why are the tram’s overhead cables positioned to make a zigzag, rather than straight line?

SolutionThe metal structure on the roof of the tram, the pantograph, rubs against the cable as the tram moves forward. If the cable was in a straight line, it would rub the same point on the pantograph, which would begin to fray. But if the cable is in a zigzag, the rubbing happens evenly across the top of the pantograph, and the pantograph wears down less quickly.

  1. Read the question

  2. What isnever odd or even?

Solution‘never odd or even’ is a palindrome, i.e. it reads the same back to front.

  1. Catch the cat

A straight corridor has 7 doors along one side. Behind one of the doors sits a cat. Your mission is to find the cat by opening the correct door. Each day you can open only one door. If the cat is there, you win. If the cat is not there, the door closes, and you must wait until the next day before you can open a door again.

If the cat was always to sit behind the same door, you would be able to find it in at most seven days, by opening each door in turn. But this mischievous moggy is restless. Every night it moves randomly either one door to the left or one to the right. Although if it is behind the first or last door, it has only one option for where it can move.

How many days do you now need tomake sure you cancatch the cat?

Solutionten days

  1. Mystery number

I have a ten digit number,abcdefghij. Each of the digits is different, and

ais divisible by 1

abis divisible by 2

abcis divisible by 3

abcdis divisible by 4

abcdeis divisible by 5

abcdefis divisible by 6

abcdefgis divisible by 7

abcdefghis divisible by 8

abcdefghiis divisible by 9

abcdefghijis divisible by 10

What’s my number?

[To clarify:a, b, c, d, e, f, g, h, i,andjare all single digits. Each digit from 0 to 9 is represented by exactly one letter. The numberabcdefghijis a ten-digit number whose first digit isa, second digit isb, and so on. It does not mean that you multiplyaxbxcx…]

Solution3816547290

  1. Disappearing cub

This picture has not been doctored. Explain why the reflection has a yellow lion cub.

Solution: The cub is camouflaged by a cleverly-coloured flap

  1. Crazy triangle

Show that there is a triangle, the sum of whose three heights is less than 1mm, that has an area greater than the surface of the Earth (510m km2).

Solution

Here’s one:

  1. Deck dilemma

Your friend chooses at random a card from a standard deck of 52 cards, and keeps this card concealed. You have to guess which of the 52 cards it is.

Before your guess, you can ask your friend one of the following three questions:

is the card red?

is the card a face card? (Jack, Queen or King)

is the card the ace of spades?

Your friend will answer truthfully. What question would you ask that gives you the best chance of guessing the correct card?

SolutionIt doesn’t matter.In all three cases, your chance of guessing the correct card is 1 in 26.

  1. The question with no question

(a) All of the following.

(b) None of the following.

(c) Some of the following.

(d) All of the above.

(e) None of the above.

[Just to reassure you, nothing has been omitted here.]

Solution(b)

  1. Triangle fold

Find a way to fold a square piece of paper into an equilateral triangle. The triangle can be of any size.

SolutionHere is one way,that uses the side length of the square as the side length of the triangle.

I hope you enjoyed these puzzles. I’ll be back in two weeks.

Sources: 1. Adrian Paenza, 2. Kvantik magaizine, 3. Des MacHale, 4. New York Times. 5. John Conway, 6. Matt Pritchard, 7. Trần Phương, 8. Henk Tijms, 9. Parabola, 10. The Paper Puzzle Book.

I set a puzzle here every two weeks on a Monday. I’m always on the look-out for great puzzles. If you would like to suggest one,email me.

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Source: The Guardian