Speed of a boat in still water is 10 km/h and the speed of the stream is 5 km/h. Find the total time taken to travel a distance of 20 km upstream and 30 km downstream

The downstream speed of a boat is 20 km/hr and the speed of current is 5 km/hr. What is the total time (in hours) taken by the boat to cover 80 km upstream and 100 km downstream?