Answer: A. 15
Explanation:
Let's look at it this way -
An object went 1/20 of the path in 3/4 of a second. Which means that for the object to go the full path it needs to go 20/20 of the path.
3/4 * 20 = 15
20 is the amount of times the object can go in 3/4 of a second.