If you are trying to figure out how much it will cost:
8 x 4 = 32
Cost of gas = $32
Kinetic engery = -1/2mv^2
Work = Fd
Combine:
-1/2mv^2 - Fd = 0
-1/2mv^2 = (0.30*15000*9.81*cos(6))d = 0
Multiply both sides by 2:
v^2 = 2d(0.30*9.81*cos(6))
Solve for d:
d=v^2 / 2(0.30*9.81*cos96))
v = speed:
d = 35^2 / 2*0.30 * 9.81 * cos(6)
d = 1225 / 5.85376
d = 209.27 meters. Round answer as needed.
Just guess and check. For example, for the first on the left, I guessed 3 to begin with. 3 + 3 + 3 = 9, but 10 + 3 = 13, so 3 is not the answer. I then guessed 5. 5 + 5 + 5= 15, and 10 + 5= 15, so star = 5.
