The boat for 1.4 h passed 2.2 km less across the current than for 1.7 h against the current. find watercourse speed. if boat speed in still water of 28 km/h.

Since the beginning we find how many km there passed the boat across the current knowing speed in still water and taking river speed for X (28+X)*1.4 further by analogy we find distance against the current (28-X)*1.7 from a condition: (28+X)*1.4+2.2=(28-X)*1.7 after all calculations on the calculator we receive X =2 km/h
Answer add