On Friday I posted this puzzle.
I am thinking of a 5-digit number. If you put ‘1’ at the beginning of the number you get a number that is three times smaller than if you put ‘1’ at the end of the number. What number am I thinking of?
If you have not tried to solve it, have a go now. For everyone else the answer is after the break.
The answer is ‘42857’ (142857 is three times smaller than 428571) – did you solve it and, if so, how?
I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for the Kindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.