We will have the information given represented by a graph in the cartesian plane.
In this case, the x-axis on the plane represents the time (in seconds) and the y-axis represents the height of the rocket (in this case, the units for the height are feet).
Thus, the graph will have the following axis:
The two axis x and y relate a time to a certain height.
We are told that the rocket reaches a maximum height of 200 ft, and it stays in the air for 20 seconds.
Remember that the graph of the projectile motion looks like a parabola, so the graph will look as follows:
We can see that the maximum height is 200 ft and the total time between the rise and the fall of the rocket is 20 seconds.