Category Archives: Puzzles

Puzzle #180: White and Black Beans

Posted on May 14, 2017 by Alok Goyal

This is a wonderful puzzle for all ages from Alok Mittal’s weekly Math Circles class. The puzzle is doable by everyone, so please do try yourself and also have your children try this one. A pot contains 75 white beans … Continue reading →

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Puzzle #179: Crossing the River

Posted on May 7, 2017 by Alok Goyal

After a rather difficult puzzle, here is an easy one, should take just a few minutes even for children, please do try! This one is from the site mathsisfun.com. Four adventurers (Alex, Brook, Chris and Dusty) need to cross a … Continue reading →

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Puzzle #178: Minarets of Samarra

Posted on April 30, 2017 by Alok Goyal

This is a wonderful puzzle contributed by Alok Mittal, through his Maths Circles class. There is one great minaret in Samarra, but what if the Caliph decided to build twelve? Since the Caliph loves regular geometry, he decides to build … Continue reading →

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Puzzle #177: How Many Times You Can Measure

Posted on April 23, 2017 by Alok Goyal

This is a variation of Puzzle #14 (https://alokgoyal1971.com/2013/04/28/puzzle-14-measuring-time/) that I found on the site fivethirtyeight.com. A fantastic puzzle! Suppose you have four ropes and a lighter. Each rope burns at a non-constant rate but takes exactly one hour to burn … Continue reading →

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Puzzle #176: Outsmart Your Teacher

Posted on April 16, 2017 by Alok Goyal

This is a relatively simple puzzle from fivethirtyeight.com, a site from which I have posted many puzzles in the past. Variations of such puzzles have been posted in the past. I would encourage parents to try this with their children. … Continue reading →

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Puzzle #175: The Three Bag Puzzle

Posted on April 9, 2017 by Alok Goyal

Apologies for a long break, I was in the middle of some hectic travel, both for personal and business reasons. But normal service resumes 🙂 Thanks to Suman Saraf yet again for recommending this puzzle. A variation of this puzzle … Continue reading →

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Puzzle #174: Happy Birthday!

Posted on March 12, 2017 by Alok Goyal

This is a very nice puzzle from fivethirtyeight.com (thanks to Suman Saraf for pointing this site to me). It’s your 30th birthday, and your friends got you a cake with 30 lit candles. You try to blow them out, but … Continue reading →

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Puzzle #173:Diving a Circle Into 7 parts

Posted on March 5, 2017 by Alok Goyal

This is yet another wonderful puzzle sent by Suman Saraf. Thanks Suman! Given a circle and it’s diameter, how can you partition it’s area into seven equal regions without using straight lines. As always, please send your answers as comments … Continue reading →

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Puzzle #172: Divisibility by first 13 numbers

Posted on February 26, 2017 by Alok Goyal

I acquired a new book recently (thanks to Suman Saraf) – Problem Solving Strategies in Mathematics. Here is a problem from that book. It is a simple problem for adults, so will request people to show it to their children. … Continue reading →

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Puzzle #171: Buying Dimsums

Posted on February 19, 2017 by Alok Goyal

This is a beauty of a puzzle sent by Suman Saraf – thanks Suman! A fast food restaurant sells dimsums in boxes of 7 and 3. What’s the greatest number of dimsums a person cannot buy. Generalize it for p … Continue reading →

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