Given parameters:
Distance to hardware shop = 5 miles
Time to reach hardware shop = 10 minutes
Time spent at the shop = 30 minutes
Average speed to customer home = 45 mph
Time taken for the travel = 20 minutes
Unknown:
Average speed of the contractor = ?
Solution:
Average speed is the total distance covered divided by the total time taken.
Average speed =
total distance = distance to hardware shop + distance to customer's home
We do not know the distance to customer's home but we have been given the speed and time, so we can find the distance.
Distance = speed x time
Convert the time to hrs and solve;
60 minutes = 1 hr
20 minutes = =
So, Distance = 45mph x = 15miles
Now;
Total distance = 5 + 15 = 20miles
Total time = time to reach hardware shop + time to reach customer's house
= 10 + 20
= 30 minutes
Convert the time from minutes to hrs;
60 minutes = 1hr
30 minutes = = 0.5hr
So;
Average speed = = 40mph
The average speed is 40mph