Answer:
4
Step-by-step explanation:
With either pass you have to add $20 per day, so you can ignore that
Assuming he goes "x" days to sky you can calculate the days he has to go to equal $300.
300 = 79x
x = 300/79 = 3.8 days
If he goes 4 days to sky it costs 316, so in that case its cheaper to buy the season pass