Compare the numbers 5.0 and 0.5.how many times 0.5 is 5

Astuntman jumping off a 20-m-high building is modeled by the equation h=20-5t^2, where t is the same in seconds. a high-speed camera is ready to film him between 15m and 10m above the ground. for which interval of time should the camera film him?

Which one ? is the answer and how to find this answer

Ascatter plot with a trend line is shown below. which equation best represents the given data? y = x + 2 y = x + 5 y = 2x + 5