Correct Answer: (1) 9 km/hr
Note: According to the question current (w) and speed of boat (y)
= 12km / h * r
Speed of current ( omega)= 1.5km / hr
.:. Speed of boat (y) = 12 - 1.5 = 10.5 km/hr
.:. Against the current men speed
= y - w = 10.5 - 1.5 = 9km / h * r