It’s the Friday Puzzle!

John wants to toss a coin to make a random decision.

However, he only has a biased coin (that is, a coin that does not have a 50:50 chance of coming up heads or tails).  Even worse, John doesn’t know the extent of the bias, and thus has no idea about the likelihood of obtaining a head or tail.

How can John toss the coin to make a 50:50 random decision?

As ever, please do NOT post your answers, but do say if you think you have solved the puzzle and how long it took. Solution on Monday.

Yesterday we had a Rip It Up caption competition.  Here was the image:

I thought that the best caption came from Dominic Twose - “I’d leave it five minutes if I were you.” Congrats Dominic, drop us an email and we will get a signed book to you.

And finally, here is a little interview with my good self revealing exactly what Rip It Up is all about…