An ordinary \(6\)-sided die has a number on each face from \(1\) to \(6\) (each number appears on one face). How many ways can I paint two faces of a die red, so that the numbers on the red faces don't add up to \(7\)?
Combos that don't add to 7 are
[ 1. 2 ] [1,3 ] [1, 4 ] [1,5 ]
[ 2, 3 ] [ 2, 4 ]
6 ways