Answer:
7:00
Step-by-step explanation:
First I figured out the MPH for the ride there by dividing 350 by 5 which was 70 MPH which is the average rate of speed. Next, I subtracted by 20 since the ride home his average speed was 20 less than before which got me 50 MPH. Then, I divided 350 by 50 to get the hours it took him with his setback which was 7. Lastly, I added 7 hours to noon (12:00) and got 7:00