This tells you that at 4.25 seconds into their flights, both the Rocket and the Drone were at a height of 20 feet.
Step-by-step explanation: The point where the two graphed lines cross is where the values are equal.
The Drone has been hovering at 20 feet between 2 and 5 seconds. The Rocket passed through that height for a brief (millisecond) time as it was falling back to the ground.
Without grid lines it is my best estimation (using a ruler to create a verticla line from the intersection of the lines to the time scale) that t = 4.25. It is between 4 and 4.5 seconds.
