The combined speeds of boats 'P' and 'Q' in still water

Solution

ATQ, Speed of boat ‘P in still water be ‘p’ km/hr Therefore, speed of boat ‘Q’ in still water = (52 – p) km/hr Let the speed of the current for boat ‘Q’ be q km/hr Therefore, speed of current for boat ‘P’ = 1.25q km/hr According to the question, (p + 1.25q) = 1927/47 = 41 ….. (1) Also, (52 – p + q) = 1927/41 = 47 …. (2) On solving equation (1) and (2), we get Speed of boat ‘P’ in still water = p = 21 km/hr Speed of the current for boat ‘Q’ = q = 16 km/hr Therefore, speed of the current for boat ‘P’ = 1.25q = 20 km/hr Therefore upstream speed of boat ‘P’ = p – 1.25q = 21 – 20 = 1 km/hr