Einstein's election riddle: are you in the two per cent that can solve it?

Last month I blogged about a logic puzzle that had gone viral in Singapore. My posts on Cheryl’s birthday problem attracted more readers than anything I have ever written before: more than five million views. For a couple of days they were the most popular stories across the entire Guardian website.

The lesson is: we all love a good logic puzzle!

So here’s another one. Like the Cheryl problem, it is a reworking of an old classic. According to puzzle lore, this one was devised by Albert Einstein as a boy and is popularly called “Einstein’s Riddle”.

It is also said that only two per cent of the population are smart enough to solve it.

Can you solve the maths question for Singapore schoolkids that went viral? Read more

Many variations have appeared over the years, including a simplified version in Harry Potter and the Philosopher’s Stone. Here I’ve updated the puzzle to reflect the 2015 Election, and the news story two weeks about the woman who painted stripes on her Kensington house in a protest about planning regulations.

You may or may not be in the one per cent. But are you in the two per cent?

There are five houses with the outside walls painted in five different ways. David, Ed, Nick, Nicola and Nigel each live in one of the houses. They each drink a certain type of coffee, have a preferred mode of transport and keep a certain pet. No owners have the same pet, the same preferred mode of transport or drink the same type of coffee.

WHO OWNS THE FISH?

Nicola lives in the tartan house.

Ed has a guinea pig

David drinks mochaccino

The paisley house is on the left of the gingham house The owner of the paisley house drinks flat whites. The person who drives by car has a squirrel.

The owner of the striped house travels by bike.

The person living in the centre house drinks double espresso.

Nick lives in the first house.

The person who travels by train lives next to the one who has a pitbull.

The person who has a badger lives next to the person who travels by bike.

The person who travels by plane drinks chai latte.

Nigel goes everywhere by foot.

Nick lives next to the polka dot house.

The person who travels by train has a neighbour who drinks decaf.



For the sake of clarity: the houses are adjacent to each other in a line and the directions are from the perspective of someone looking at the houses. And any resemblance of David, Ed, Nick, Nicola and Nigel to the party leaders is purely coincidental. You have to solve this problem by logic, not by having had a coffee with any of them.



It’s a bank holiday, so no excuses for not having a try.

I’ll post the solution later.

I’ll be starting a regular puzzle column on the Guardian science blog network later this month. Please email me with your favourite puzzles and I’ll try to feature the best ones in the column.

My latest book Alex Through the Looking-Glass: How Life Reflects Numbers and Numbers Reflect Life is just out in paperback.

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