Answer:
O 81 km per hour
Explanation
Given parameters:
Number of days traveled = 3 days
Distance covered on the first day = 1080km
Time of travel = 10hrs
Rate of travel = 108km/hr
Time of travel on second day = 12hrs
Rate of travel = 90km/hr
Time of travel on third day = 18hrs
Rate of travel = 60km/hr
Unknown
Average speed = ?
To find the average speed, we sum the distances and divide by the sum of the time.
Average speed =
we do not know the second and third distances;
Distance = speed x time
D2 = 90 x 12 = 1080km
D3 = 60 x 18 = 1080km
Now;
Average speed =
Average speed = = 81km/hr
The average speed is 81km/hr