a) Answer;
= 6.72 hours
Explanation and solution;
velocity = distance over time
Since we know the velocity and the distance, we can simply calculate time
For the first part
85 km/h = 300km / time
time = 3.53 hours
Then there is a 22 min stop, which is the same as 0.37 hours
so far the trip is:
3.53 + 0.37 = 3.9 hours
then for the last stretch:
78 km/h = 220 km / time
time = 2.82 hours
So the total trip is:
3.9 + 2.82 = 6.72 hours
b) Answer;
= 77.38 km/hr
Explanation and solution;
we take the total distance divided by the total time to get the average.
total distance = 300 km + 220 km = 520 km
total time = 6.72 hours
Average velocity = 520 km / 6.72 hours = 77.38 km/hr