given below

Let x be the speed of the boat in still water.

 

Then the speed of the boat in upstream is x - 2 km/h and the speed of the boat in downstrem is x + 2 km/h.

 

Distance covered in upstream is 30 km.

 

Therefore, the time taken to cover a distance of 30 km upstream is

And the time taken to cover a distance of 30 km downstream is

 

Given that the time taken by the motor boat in upstream exceeds the time taken by the boat in down stream by 2 hours.

 

Therefore, we have