Ok so basically, the number of student tickets is 3x, where x=the number of adult tickets sold. And we know that s(for student tickets)+x=480 total tickets sold. So if we replace s with 3x we have 3x+x=480, or 4x=480. We divide by 4 and get x=120, which is the amount of adult tickets sold.
The given function is

According to this function, the starting height of the rocket is 20 feet because that's the initial condition of the problem stated by the independent term.
Additionally, we find the maximum height by calculating the vertex of the function V(h,k).

Where a = -16 and b = 300.

Then, we find k by evaluating the function

Hence, the maximum height is 1426.25 feet.
At last, to know the time need to hit the ground, we just use h=9.375 and we multiply it by 2

Hence, the rocket hits the ground after 18.75 seconds.
I don’t know if this helps but…
Slope: 2/3
Y-intercept: (0,-4)