If the first roll is a 4, the possibilities to add less than 8 are that the second cube roll is 1, 2 or 3.
These are 3 different events out of 6 possilbe ones, which is 3 / 6 = 1 / 2; i.e. half of times.
Then the answer is the first option: 1 / 2
C = 4500 + 150s
4500 is fixed, so what remains is just 150$ per ton of sugar (so 150 x s)
If we substitute 12 for s we get:
C = 4500 + 150*12
C = 6300
