Since we want to find the number of trips to the park for which paying daily admission is more expensive than purchasing a season pass, we can express an inequality, like this:
total daily admission cost > season pass cost
The total daily admission cost, can be expressed as the number of days that this pass is purchased (n) times the daily admission cost ($39), and the season pass cost equlas $117, then we get:
$39*n > $117
From this expression we can solve for n, then we get:
Then, more than 3 daily passes would be more expensive than the season pass. Since it must be more than 3, the answer is 4 trips