#15 Domino strips
Set by Peter Rowlett
There are three ways to cover a 3 × 2 grid with dominoes.
How many ways are there to cover a 4 × 2 grid? What about a 6 × 2 grid?
Can you find a pattern that would help you work out the number of different ways dominoes can be used to cover any n × 2 rectangle?
Solution next week
#14 Factor graphs
Solution
Here’s a factor graph of 1-10:
You can connect every number up to 14, but adding 15 requires drawing lines to 3 and 5, which leads to crossing. If we exclude…
