Question

alina drives 20 miles from her home to the store at a speed of 30 miles per hour.if she makes the return trip home at a speed of 40 miles per hour, what is the total amount of time she spent driving​

Answer 1

Answer:

The car covers 20 miles at a speed of 30 mph. So the time taken to cover 20 miles 20*60/30 = 40 min.

Next, it covers 20 miles at a speed of 40 mph. So the time taken to cover 20 miles 20*60/40 = 30 min.

Lastly, it covers 20 miles at a speed of 50 mph. So the time taken to cover 20 miles 20*60/50 = 24 min.

So the total distance covered is 20+20+20 or 60 miles in 40+30+24 = 94 min.

Therefore the average speed = 60*60/94 = 38.29787234 mph.