A boat goes upstream for 3 hours and then downstream for the same time. If the speed of the current is 3.5 kmph, how far from its original position is the boat now?
Speed of boat in still water = X
Speed of stream = Y
Upstream speed = X – 3.5
Downstream speed = X + 3.5
I am stuck here. How to calculate the extra distance that boat has traveled?
After seeing Ross's answer: What does 21 mean?
I draw two possibilities of 21 km in this diagram: