A regular octahedron has sides numbered 1, 3, 5, 7, 9, 10, 11, 12. Another regular octahedron has sides numbered 2, 4, 6, 8, 9, 10, 11, 12. How many different sums can be obtained if these are thrown together, and the numbers on the top faces are added?

a) 18

b) 64

c) 15

d) 19

e) 17

Guest Dec 16, 2017