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 | Play the magician
Here are two tricks to play on your friends, one with playing cards and the other with birthdays and anniversaries. What makes each of them work?
Published on May 05, 2025 08:07 AM IST
Problematics | Wage hikes
Try this puzzle with multiple variables. If the annual increments of six workers are given to you, can you work out their current wages?
Published on Apr 28, 2025 11:18 AM IST
Problematics | Walking on an escalator
4 experimenters walk up and down 3 moving escalators, varying their speeds and number of steps. How many steps will you see in each escalator if switched off?
Updated on Apr 22, 2025 04:47 PM IST
Hycean worlds: A new frontier in search for extraterrestrial life
Scientists have found strong signs of possible life on exoplanet K2-18b, a potential "Hycean world," suggesting new avenues in the search for alien life.
Published on Apr 18, 2025 06:32 AM IST
Kabir Firaque, New Delhi
Problematics | Around the world in 79 days
Fogg’s miscalculation and subsequent correction can be explained with longitudes. Is there any other mathematical way to explain what went wrong and then right?
Updated on Apr 14, 2025 02:27 PM IST
Problematics | The renovated guesthouse
Given two bills for paint, lights and fans without being told any of the individual prices, can you work out the amount of a refund?
Updated on Apr 07, 2025 01:07 PM IST
Problematics | Matches with sachets
Matchboxes and shampoo sachets are bought and then sold at a profit. With limited information, can you find out how many there are of each?
Updated on Mar 31, 2025 08:20 AM IST
Problematics | Music old style
This week’s puzzle revisits the record player. What distance does the stylus, or needle, travel along an LP disc?
Published on Mar 24, 2025 11:25 AM IST
Problematics | Chaplin vs Ray vs Hitchcock
They are part of a bowling line-up with Kurosawa and Renoir completing the attack. Find out which bowler took how many wickets in how many overs.
Published on Mar 17, 2025 10:16 AM IST
Problematics | A winner from long ago
You have one tournament, six teams, and about half a dozen trends. Find the results of all 18 matches.
Published on Mar 10, 2025 01:31 PM IST
Problematics | Dining couples
Two couples eat lunch and dinner together for seven days in a row. Who plays which bill for the 14 meals?
Published on Mar 03, 2025 04:11 PM IST
Problematics | The rate of gunfire
A gunmaker claims he can fire his weapon at a certain rate. Has he delivered what he promised?
Updated on Feb 24, 2025 03:45 PM IST
How Delhi's Jantar Mantar read the cosmos
The Jantar Mantar has three instruments built by Sawai Jai Singh to observe celestial coordinates. Ahead of its restoration, a look at all the instruments.
Updated on Feb 21, 2025 06:24 PM IST
Problematics | Siblings who bowl and bat
Four brother-sister pairs play some matches and score some runs. Who is whose sibling, and who scores how much in how many matches?
Updated on Feb 17, 2025 12:35 PM IST
Problematics | Superhero fact and fiction
Which one(s) among Superman, Batman and Robin tell(s) the truth, and which one(s) lie?
Updated on Feb 10, 2025 08:31 AM IST
Problematics | Dinner with Oscar non-winners
Here’s an Einstein puzzle that celebrates Alfred Hitchcock, Charlie Chaplin, Marilyn Monroe among 15 legends who never won an Oscar during their lifetimes.
Published on Feb 03, 2025 04:05 PM IST
Problematics | The truth about drinking
Two habitual liars and a truthful friend get drunk in a bar. Who drinks what?
Updated on Jan 27, 2025 10:14 AM IST
Problematics | Cubic calendar
Two cubes, a little larger than ludo dice, carry some digits that you can see and some that you cannot. What are the ones you cannot see?
Published on Jan 20, 2025 02:29 PM IST
Problematics | Books on a library shelf
Hundreds of books on seven library shelves, unevenly distributed before being shared equally. How many were on each shelf in the beginning?
Published on Jan 13, 2025 02:26 PM IST
Problematics | Who owns the zebra in 2025?
An Einstein puzzle that borrows an iconic character from the original puzzle that's attributed to the great scientist. Try it. It’s less difficult than it looks
Published on Jan 06, 2025 08:11 AM IST
Problematics | Stolen coins
Five thieves get unequal shares from a set of coins stolen from the museum. Who gets how many coins?
Updated on Dec 30, 2024 11:38 AM IST
Problematics | Movie jumble
Before the mathematical puzzle, have some fun with words by unscrambling anagrams of 10 movie titles.
Published on Dec 23, 2024 01:41 PM IST
Problematics | Cards on the table
Here is yet another trick with a deck of 52 that you can perform on a gullible audience. As usual, let us examine the mathematics that makes the trick work.
Published on Dec 16, 2024 02:54 PM IST
Willow: What Google’s error-correcting chip means for quantum computing
Willow improves on Google’s earlier work, published in early 2023, when it described an array of 49 qubits in its Sycamore quantum processor
Updated on Dec 12, 2024 05:15 AM IST
Kabir Firaque, New Delhi
Problematics | The uncle and the grandmother
A mathematician has two children, a brother and her mother; determine the ages of all four
Updated on Dec 09, 2024 07:20 PM IST
Problematics | Where Hitchcock meets Einstein
This week, an Einstein puzzle with Hitchcock movies rather than zebras, and an easier teaser that may look deceptively difficult.
Published on Dec 02, 2024 09:26 AM IST
Problematics | Russian eggs for sale
Three sisters sell eggs at the same price and earn the same amount of money for different numbers of eggs. How is that possible?
Published on Nov 25, 2024 08:32 AM IST
Problematics | Rescue dog
You know the length of the ladder being used to rescue a dog from a window. Can you work out the height of the window?
Published on Nov 18, 2024 11:43 AM IST
Problematics | A clockwork montage
This week, two puzzles involving clocks, both unique and associated with illustrious personalities in mathematics.
Published on Nov 11, 2024 10:23 AM IST
Problematics | When couples bought and sold puzzles
This week, a tweaked version of an unusual puzzle that was first published more than 200 years ago.
Updated on Nov 04, 2024 06:45 PM IST