To find the rate in still water, we need to find the average speed of the boat. The total distance traveled by the boat is 192 + 360 = 552 kilometers. The total time taken is 3 + 4 = 7 hours.
So, the average speed of the boat is 552/7 = 78.857 km/hr.
To find the rate of the current, we need to find the difference in speed between the upstream and downstream journeys. The difference in speed is 360/4 - 192/3 = 90 - 64 = 26 km/hr.
So, the rate of the current is 26 km/hr.
Therefore, the rate in still water is 78.857 km/hr and the rate of the current is 26 km/hr.