Copyright © University of Cambridge. All rights reserved.
'Light the Lights' printed from http://nrich.maths.org/
Here is a machine with four coloured lights. Each light responds to
When you type in a number, lights go on if their rule is satisfied.
If the number satisfies more than one rule, then more than one
colour will light up
Type in some numbers and see which lights you can switch on.
What is the smallest number which lights them all up?