#16 Order, order!
Set by Katie Steckles
Arrange the digits 1-9 in a line so that each pair of adjacent digits differs by either 2 or 3.
Arrange the digits 1-9 in a line so that each pair of adjacent digits sums to a prime number.
Now arrange the digits 1-9 in a line so that each pair of adjacent digits (when read as a two-digit number) appears in the times tables from 1 × 1 up to 9 × 9.
Solution next week
#15 Domino strips
Solution
There are five ways to cover a 4 × 2 rectangle and 13 ways…