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Kabir Firaque

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

Problematics | Playing cards, words and a classroom game

Have you ever created something, like a poem or a word game, only to find that someone else has created something similar? This week's puzzles are one of those.

Welcome to Problematics! (Shutterstock)
Updated on Feb 10, 2023 09:04 AM IST

Why earthquakes happen, and how to measure them

While the difference in the magnitude between the two earthquakes is a mere 0.3, the second one is two times bigger than the first, and released 2.8 times more energy, according to an online tool hosted by the US Geological Survey

People walk amid rubble following an earthquake in Hatay, Turkey, February 7, 2023. REUTERS/Umit Bektas (REUTERS)
Published on Feb 07, 2023 09:39 PM IST

Problematics | More tricks to play on impressionable friends

Welcome to week 23 of Problematics! Here are this week's puzzles, admittedly not my own.

Welcome to Problematics! (Shutterstock)
Updated on Jan 30, 2023 04:57 PM IST

Problematics | The puzzling truth about cats and dogs

For any Monday’s puzzles, please send in your solutions by noon on Friday the same week. This will also be mentioned in the footnote every week. Let's get solving!

Welcome to Problematics! (Shutterstock)
Published on Jan 23, 2023 07:04 PM IST

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?

Sister Andre, Lucile Randon in the registry of birth, the eldest French and European citizen, prays in a wheelchair, on the eve of her 117th birthday.
Updated on Jan 20, 2023 01:56 PM IST
By, New Delhi

Problematics | Think of a number, repeat and recycle

This week's fare is relatively simple, although the puzzles are not exactly sitters.

Welcome to Problematics! (Shutterstock)
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.

Welcome to Problematics! (Shutterstock)
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.

Welcome to Problematics! (Shutterstock)
Published on Jan 02, 2023 01:24 PM IST

Problematics | The mathematics of planning a family

Here's week 18 of Problematics.

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.

Welcome to Problematics! (Shutterstock)
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

N-fusion: The clean energy the world needs, but may not get soon enough
Updated on Dec 13, 2022 10:51 AM IST
By, 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!

Welcome to Problematics! (Shutterstock)
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.

Welcome to Problematics! (Shutterstock)
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.

Rolls Royce AE2100 Hydrogen Test at Boscombe Down. (Rolls Royce)
Updated on Nov 29, 2022 02:16 PM IST
By, 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.

Welcome to Problematics! (Shutterstock)
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.

Welcome to Problematics! (Shutterstock)
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:

Welcome to Problematics! (Shutterstock)
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.

Welcome to Problematics! (Shutterstock)
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:

Rescue personnel conduct search operations after a bridge across the river Machchhu collapsed at Morbi in Gujarat. (AFP)
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.

Welcome to Problematics! (Shutterstock)
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.

In mustard, however, crossing two different breeds is a challenge because the crop is self-pollinating, which means that the offspring are produced by the male and female organs of the same plant. (AFP Representational Photo)
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.

Somewhere in the cells of our brains lies the key to what we call sentience, or the ability to sense, feel, and be conscious of what is happening around us. (Twitter)
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.

Welcome to Problematics! (Shutterstock)
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.

A firecracker consists of three main components: a fuel, an oxidiser, and a binder. (Representative Image)
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.

Welcome to Problematics! (Shutterstock)
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.

Welcome to Problematics! (Shutterstock)
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.

Barry Sharpless and Morten Meldal developed click chemistry; Carolyn R Bertozzi developed click reactions inside a living cell. (Johan Jarnestad/The Royal Swedish Academy of Sciences)
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.

Secretary General of the Royal Swedish Academy of Sciences Hans Ellegren, centre, Eva Olsson, left and Thors Hans Hansson, members of the Nobel Committee for Physics announce the winner of the 2022 Nobel Prize in Physics, from left to right on the screen, Alain Aspect, John F. Clauser and Anton Zeilinger in Stockholm on Tuesday. (AP)
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?

Ancestors of modern humans interbred with Denisovans and Neanderthals after migrating out of Africa, starting about 70,000 years ago (
Updated on Oct 05, 2022 10:46 AM IST
By, 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:

Welcome to Problematics! (Shutterstock)
Updated on Oct 03, 2022 01:45 PM IST
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