Puzzles Editor Kabir Firaque is the author of the weekly column Problematics. A journalist for three decades, he also writes about science and mathematics.
Articles by Kabir Firaque
A timeless debate: How long can a human live?
The death of French nun Lucile Randon, known as Sister André, at age 118 — in fact, 25 days short of her 119th birthday — has revived the perennial question: how long can a person realistically hope to live?
Updated on Jan 20, 2023 01:56 PM IST
Kabir Firaque, New Delhi
Problematics | Think of a number, repeat and recycle
This week's fare is relatively simple, although the puzzles are not exactly sitters.
Published on Jan 17, 2023 03:43 PM IST
Problematics | Watch your hands and how they move
Ignore the second hand and concern yourselves only with the hour and minute hands. Like last week’s Christmas tree puzzle, this one too comes from something I had presented to readers 30 years ago.
Published on Jan 10, 2023 03:34 PM IST
How long does it take to set up an Xmas tree?
I felt the puzzle would work better if I adapted it for readers who are three decades younger. I have changed the form of the original but retained the content.
Published on Jan 02, 2023 01:24 PM IST
Problematics | The mathematics of planning a family
Here's week 18 of Problematics.
Updated on Dec 26, 2022 03:13 PM IST
Problematics | A puzzler’s guide to matchmaking
Here's week 17 of Problematics.
Updated on Dec 20, 2022 02:40 PM IST
N-fusion: The clean energy the world needs, but may not get soon enough
For the first time, a nuclear fusion experiment has achieved ignition, generating more energy that it consumed. While there are miles to go before fusion can become the source of the world’s energy needs, the results mark a milestone in scientific terms
Updated on Dec 13, 2022 10:51 AM IST
Kabir Firaque, New Delhi
Problematics | Flight of fancy: Around the world in how many days?
When someone identifies an error in someone else’s puzzle, it is called “cooking” the puzzle. Here's a simplified adaptation for readers of Problematics!
Updated on Dec 12, 2022 05:24 PM IST
Problematics | Which game is smarter, poker or teen patti?
The Hollywood caper The Sting (1973) includes a memorable depiction of a poker game, in which a lot of cheating is going on. This too is about poker, and the rules of the game now may help you warm up for The Sting later.
Updated on Dec 06, 2022 09:07 AM IST
Can hydrogen-fuelled engines be the next big leap in aviation?
In the test on a hydrogen-driven aero engine, Rolls-Royce and easyJet appear to have overcome a crucial challenge that is often mentioned when hydrogen engines are discussed — although hydrogen is meant to be a green fuel, it is produced using electricity, and generating that electricity can involve burning of fossil fuels.
Updated on Nov 29, 2022 02:16 PM IST
Kabir Firaque, New Delhi
Problematics | How the crow flies between World Cup football fans
The football World Cup provides the ideal occasion to release a puzzle that I had so far been holding on to. It’s not about football, but involves fans of the game. And it’s not extremely difficult, but it’s fun when you figure out how to solve it.
Published on Nov 28, 2022 01:25 PM IST
Problematics | World Cup goals set on your table
The World Cup is an occasion we cannot ignore. I hope you enjoy solving the following football-related puzzles as much as I enjoyed creating them.
Updated on Nov 22, 2022 01:16 PM IST
Problematics | Play Wordle with these movie titles
Neither of this week’s puzzles is exceptionally tough, but one will require harder work than the other. That one is not mathematical, but a word puzzle that also requires some knowledge of Hollywood:
Published on Nov 15, 2022 12:24 PM IST
Problematics | The weight of a bulldog and friends
The following kind of puzzle is one involving two equations and three variables, whose values you need not determine while getting to the answers you are looking for.
Published on Nov 07, 2022 02:27 PM IST
The science behind the load, span and design of a safe bridge
Different kinds of bridges require different factors to be taken into consideration. HT explains:
Published on Nov 01, 2022 09:46 PM IST
Problematics | One step at a time on Metro escalator
It would be a stretch to describe what follows as an original puzzle, but I have tinkered with a couple of existing forms of puzzles and merged them into one using my own variables.
Updated on Oct 31, 2022 03:02 PM IST
Decoding the science behind genetically modified mustard
To modify any variety of a crop so that it incorporates the desirable qualities from another variety, the obvious approach is to breed one with the other.
Updated on Oct 27, 2022 01:23 AM IST
Brain cells play a game: Are they 'conscious'?
To better understand how the brain works, scientists have now cultured human and mouse neurons in a dish and trained them to play a computer game outside the body.
Published on Oct 25, 2022 06:31 PM IST
Problematics | Poker cards with a dash of chemistry
This week’s puzzles remain mildly challenging, like most of the previous ones.
Published on Oct 25, 2022 02:55 PM IST
Explainer: The chemistry of green crackers work, and how they help
Green crackers seek to produce the same light-and-sound effect as conventional crackers but emit lower amounts of pollutants. To know what ingredients they use, it is necessary to first understand what goes into a conventional cracker.
Published on Oct 24, 2022 04:01 PM IST
Problematics | From Wonderland, without Alice
Apart from his stories, Charles Lutwidge Dodgson aka Lewis Carroll, the author of Alice in Wonderland, created a number of delightful puzzles, one of which I have loosely adapted for you.
Published on Oct 17, 2022 03:44 PM IST
Problematics | Once upon a time in the wheels
There is a gem of a puzzle hidden in old cinema shots of a moving stagecoach.
Published on Oct 10, 2022 12:34 PM IST
Nobel for finding the perfect molecular click
The Nobel Prize in Chemistry, awarded on Wednesday, honours three scientists “for the development of click chemistry and bio-orthogonal chemistry”. These innovative chemistries provide efficient ways to build new molecules that have significant uses, particularly in pharmaceuticals.
Updated on Oct 06, 2022 12:33 PM IST
Deciphering quantum secrets leads to a Nobel
It is for their work on quantum entanglement that Alain Aspect, John Clauser and Anton Zeilinger shared the Nobel Prize in Physics announced on Tuesday.
Updated on Oct 05, 2022 11:42 AM IST
How Nobel winner tracked human evolution, interactions with extinct relatives
What makes human beings human? What makes us different from our closest relatives, the now extinct Neanderthals and Denisovans, and what do we have in common with them?
Updated on Oct 05, 2022 10:46 AM IST
Kabir Firaque, New Delhi
Problematics | Operation dessert mix
This week, there are only three elements and still no compulsion, but I give you A, B and C all the same. I picked these words out of three different dictionaries. Here are the puzzles:
Updated on Oct 03, 2022 01:45 PM IST
Problematics | Spot the cheetahs at the roundtable
This puzzle involves eight big cats released into a national park.
Published on Sep 26, 2022 12:42 PM IST
Problematics | Scores to settle on cricket pitch
This week on, everyone who solved one or both of last week’s puzzles gets acknowledged here, in the online version of Problematics, while the print version lists those who solved both. Here are this week's puzzles:
Updated on Sep 19, 2022 06:43 PM IST
Where the cheetah’s speed comes from
What is it that enables the fastest land mammal to reach a top speed above 100 kilometres per hour (in short bursts), accelerating from 0 to 70 in just 2.5 seconds? It is a question that continues to intrigue scientists.
Updated on Sep 17, 2022 10:45 AM IST
Kabir Firaque, New Delhi
The science behind e-scooter fires
As with any electrical device, an electric vehicle comes with its own inherent risks, but is considered safe as long as it has been tested properly and is maintained well and not abused.
Updated on Sep 15, 2022 05:29 AM IST
Kabir Firaque, New Delhi