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 | 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
Problematics | Drone up and down
A drone moves back and forth between two walkers; what is the distance it travels before the two meet?
Published on Oct 28, 2024 02:20 PM IST
Problematics | The sum of all house numbers
Here is an unusual puzzle in which you determine the number of houses on a street without being given any figures. Can you work it out?
Published on Oct 21, 2024 12:04 PM IST
Problematics | Money transfer
Here’s a simple diversion if you transfer four coins of different sizes from one location to another, following certain rules. In how many moves can you do it?
Updated on Oct 14, 2024 11:55 AM IST
Kabir Firaque, New Delhi
Nobel prize in chemistry: They used AI to decipher old proteins, make new ones
The Nobel Prize in Chemistry honors three scientists for using AI to predict protein structures, enhancing medicine and engineering new proteins.
Updated on Oct 10, 2024 06:37 AM IST
Nobel prize in Physics: They trained their machines to imitate the human brain
They are pioneers who developed early artificial neural networks. John Hopfield and Geoffrey Hinton used fundamental concepts of physics to develop their ideas
Updated on Oct 09, 2024 12:03 AM IST
Medicine Nobel: They found tiny RNA and how it regulates life’s complexity
The Nobel Prize in Physiology honors Ambros and Ruvkun for discovering microRNA, key to gene regulation and vital for cellular functions and evolution.
Updated on Oct 08, 2024 05:43 AM IST
Problematics | Nobel Prizes in other people’s subjects
In this special puzzle for Nobel week, can you figure out which award the Chilean wins, and which winner is wearing a grey suit?
Published on Oct 07, 2024 08:19 AM IST
Laddus and the science of testing ghee’s purity
Milk fat contains thousands of organic molecules called triglycerides, each structurally different, and formed with different fatty acids.
Updated on Oct 04, 2024 01:46 AM IST
Problematics | Poetry in code
Here are some verses in which every letter has been substituted with a different letter. Can you re-substitute them and find the original verses?
Published on Sep 30, 2024 11:40 AM IST
Problematics | Multiplying with playing cards
Here is an old party trick in which playing cards magically reveal the result of a multiplication exercise. What is the secret behind it?
Updated on Sep 23, 2024 10:17 AM IST
Pager bombs: The theories and the science behind them
Tuesday’s pager blasts across Lebanon, which killed at least 12 and injured nearly 3,000, have been varied in content but consistent in suggesting an orchestrated attack by Israel
Updated on Sep 18, 2024 09:05 PM IST
Problematics |The fastest way to toast a sandwich
Given a toaster that can accommodate two slices but toast only one side of each at a given time, how do you toast three slices in the most efficient time?
Published on Sep 16, 2024 09:30 AM IST
Problematics | Don Vito’s grandchildren
When the don dies, which grandson lays wreaths of which colour? And how do the Good, the Bad and the Ugly share their wealth unequally?
Published on Sep 09, 2024 09:14 AM IST
Problematics | The perfect draw at a Grand Slam
How do you make a draw such that the top four players head for the semifinals and the top two for the final?
Published on Sep 02, 2024 07:54 AM IST
Vigyan Yuva awardee Swarup Kumar Parida: Chickpea that tolerates drought
The agricultural scientist uses novel techniques for molecular breeding of superior crop varieties, particularly a drought-tolerant variety of chickpea.
Published on Aug 28, 2024 08:02 AM IST
Vigyan Yuva awardee Digendranath Swain: Structural engineering of rocket parts
The researcher at Vikram Sarabhai Space Centre designs and uses specialised tools to examine the integrity of components used in ISRO’s launch vehicles.
Published on Aug 27, 2024 03:14 PM IST
Vigyan Yuva awardee Purabi Saikia: Mapping India’s forest resources
The plant ecologist describes how her research on India’s forest resources is important to conservation and addressing climate change.
Updated on Aug 27, 2024 12:10 PM IST
Vigyan Yuva awardee Prashant Kumar: Satellite data for weather forecast
The ISRO scientist assimilates satellite and ground data optimally and customises forecasting models to Indian conditions.
Published on Aug 27, 2024 11:33 AM IST