Question

10) Spike drives for 50 miles at 60mph. He slows down and travels

Answer 1

Answer:

2 1/3 hours or 2 hours 20 minutes.

51.4 mph to 1 decimal place.

Step-by-step explanation:

Time = distance  speed

First 50 miles time taken = 50 / 60  = 5/6 hours

Second 50 miles  -  time  =  50/40 = 5/4 hours.

Final 20 miles - time taken =  20 / 80 = 1/4 hours.

Total time taken = 5/6 + 5/4 + 1/4

= 5/6 + 6/4

= 10/12 + 18/12

= 28/12

=  7/3 or 2 1/3 hours or 2 hours 20 minutes.

Average speed = total distance / total time

=  120 / 7/3

= 120 * 3/7

=  51.4 mph to 1 decimal place.