Please do NOT post your answer, but do say if you think you have solved the puzzle and how long it took. Solution on Monday.
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?
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.