Question

A man wishes to travel due North in other to cross a river 5km wide flowing due east at 3km/hr. If he can row as10km/hr in still water find either by scale or calculation.Find:(1)the direction in which he must head his boat in order to get to his destination directly opposite it's starting point (2)the resultant velocity of the boat in the river(3)the time taken to cross the river(4)how far from his destination he would land if he ignorantly stirred North ward