Answer:
<em>Scott will take 221 minutes to run 52 km</em>
Step-by-step explanation:
<u>Speed</u>
The speed of an object can be calculated with the formula:

Where d is the distance traveled and t is the time taken.
Scott can run d=20 km in 85 minutes. Thus, his speed is:

Now he wants to know how many minutes it will take him to run d=52 km. Solving the formula for t:

Since the speed has been already determined:

Multiplying by the reciprocal of the denominator:

t = 221 min
Scott will take 221 minutes to run 52 km