Answer:
20 feet
Step-by-step explanation:
You want the distance between the zeros of the function y = -11/50(x -4)(x -24), where x and y are in feet.
The function value is zero when the factors are zero:
x -4 = 0 ⇒ x = 4
x -24 = 0 ⇒ x = 24
The distance between these values on the x-axis is ...
24 -4 = 20
The width of the tunnel at ground level is 20 feet.