The formula for Average speed =
The car travels 80 km in 1 hour.
Then the car travels 90 km in 2 hours.
And finally the car travels 76 km in 1 hour
So the total distance covered by the car = 80 + 90 + 76 = 246 km
The total time taken to cover this distance = 1 + 2 + 1 = 4 hours.
So average speed =
The average speed of the car is 61.5 km / h