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 blue, so that the product of the numbers on the painted faces isn't equal to 6?
+3132
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 blue, so that the product of the numbers on the painted faces isn't equal to 6?
1 6 2 6 3 6 4 6 5 6 Looks like there are 13 ways.
1 5 2 5 3 6 4 5
1 4 2 4 3 4
1 3 2 3
1 2
.
