Hi there! The answer is 102 mph.
A car travels at a steady speed and takes 5 hours to travel 510 miles.
To work out the average speed, we only need to find the speed per hour (miles per hour - mph). Since we now have our distance covered in 5 hours, we must divide by 5.
Distance covered per hour = 510 miles / 5 hours = 102 miles per hour.
Therefore the speed is 102 mph.