Answer:
1642.86 seconds
Step-by-step explanation:
Constant Speed Motion
If an object is moving in a constant direction and travels same distances x in same times t, it's speed is constant and can be computed as

The time taken to travel x is computed by

We know Greyson must walk 500 meters to reach the highway and then 1800 meters to reach The Harding Twp Library. The total distance is 2300 meters. It's done with a constant speed of 1.4 m/s, so the time taken to get there will be

It's equivalent to 1642.86/60, approximately 27 minutes of walk