Enigma 1103: Brush strokes
7 August 2017
Posted by on
From New Scientist #2259, 7th October 2000
Our sign painter has an odd way of calculating his charges. For each continuous brush-stroke (which can be any shape but must not go over the same ground twice) he charges £1. He paints capital letters in a simple style and does not use two strokes where one would do. So, for example his U, E, G and H would cost £1, £2, £2 and £3 respectively.
My house number is a three-figure prime and I have asked the sign painter to spell out the three different digits (so that, for example, 103 would be ONE NOUGHT THREE and would cost £24). For my house number the cost in pounds equals the sum of the three digits and is also a prime.
What is my [house] number?