Counting The Spots
Standard six-sided dice are numbered from 1 to 6 and are designed to have opposite sides add up to 7. (For example, a 3 on the top means a 4 is hidden on the bottom.) When you roll a die, there are 5 visible faces and 1 invisible face.
You roll two dice and count the number of spots on ALL visible faces, getting a total of 40. What is the sum of just the top faces?