Question

It takes a ship 3 hours to cover 72 km with the current and 4 hours against the current. Find the speed of the ship in still water and the speed of the current.

Plz show work

Answer 1

Hey kid!
The ship's speed relative to the water plus the speed of the water is 24 km/h.
The ship's speed relive to the water minus the speed of the water is 18 km/h.

The difference logically is twice the speed of the water, so that is 3 km/h. This leaves a speed of 21 km/h for the boat in still water.
Another way to show this would be this Vs+Vc = 72/3 = 24 m/sec
Vs-Vc = 72/4 = 18 m/sec
subtracting one from the other :
2Vc = 24-18 = 6.0 m/sec
Vc = 3.0 m/sec.
Hope this helps ~Nadia~