Answer:
The expected sum of the numbers on the upward faces of the two dice is 7.
Step-by-step explanation:
Consider the provided information.
If two pair of dice tossed the possible out comes are:
(1, 1), (1, 2), (1, 3), (1, 4), (1, 5), (1, 6)
(2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (2, 6)
(3, 1), (3, 2), (3, 3), (3, 4), (3, 5), (3, 6)
(4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (4, 6)
(5, 1), (5, 2), (5, 3), (5, 4), (5, 5), (5,6)
(6, 1), (6, 2), (6, 3), (6, 4), (6, 5), (6,6)
Now we need to find the expected sum of the numbers on the upward faces of the two dice.
The expected sums can be:
Sum: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12
Prob: 1/36, 2/36, 3/36, 4/36, 5/36, 6/36, 5/36, 4/36, 3/36, 2/36, 1/36
As we know that the expectation of experiment can be calculated as:

Here S represents the numerical outcomes and P(S) is the respective probability.
Substitute the respective values in the above formula.

Hence, the expected sum of the numbers on the upward faces of the two dice is 7.