# Tag Archives: probability puzzles

## Puzzle #189: Blue Eyed Sisters

A very interesting two minute puzzle from Martin Gardner’s The Colossal Book of Short Puzzles and Problems. Please do share this with your children as well. If you happen to meet two of the Jones sisters (this assumes that the … Continue reading

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## Solution to Puzzle #174: Happy Birthday!

This puzzle was not an easy one, and one of the ways to make it easier was to solve it for a smaller number of candles and then try to solve for larger number of candles. There is a whole … Continue reading

## Puzzle #174: Happy Birthday!

This is a very nice puzzle from fivethirtyeight.com (thanks to Suman Saraf for pointing this site to me). Itâ€™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 #168: Who Gets the Easter Eggs?

This is a delightful and a very counterintuitive puzzle, again from the NSA collection. Original puzzle has been written by Tim C., an Applied Research Mathematician at NSA. Alice has a dozen cartons, arranged in a 3×4 grid, which for … Continue reading

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## Solution to Puzzle #161: Lost Car Key Puzzle

Apologies for not posting the answer last weekend, I was traveling again đź™‚ I guess conditional probability puzzles are not the most popular, I got correct answers only from Suman Saraf and Pratik Poddar, even though I thought that the … Continue reading

## Puzzle #161: Lost Car Key Puzzle

This is a very nice probability puzzle, variations of which we have done in the past. This one is contributed by Suman Saraf – Thanks Suman! I drive to work, and put my car keys in my pocket. Whenever I … Continue reading

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## Solution to Puzzle #149: The Funny Plane Seating

Apologies for not posting the answer earlier – I was traveling last weekend. This was a difficult problem on a relative scale, and I therefore received the correct from all the die hard puzzle solvers in addition to one my … Continue reading

## Solution to Puzzle #148: The First Black Ace

This was a bit of a Â counterintuitive puzzle – fourÂ people sent the correct answers – Suman Saraf, Pratik Poddar, Abhinav Jain and Karan Sharma – well done! The answer is the first card. It is a bit difficult to imagine … Continue reading