A fishing boat travels along the east coast of the United States and encounters the Gulf Stream current. It travels 23 miles north with the current in 1 hr. It travels 39 miles south against the current in 3 hr. Find the speed of the current and the speed of the boat in still water.

Speed of the boat 18 mph

Speed of the current 5 mph

Step-by-step explanation:

If it travels 39 miles south against the current in 3 hours then the combination speed is 39/3 = 13 miles/h.

Let x be the speed of the boat and y be the speed of the current

With the current: total speed = x + y = 23 mph

Against the current: total speed = x - y = 13 mph

We can add up 2 equations:

x + y + x - y = 23 + 13 = 36

2x = 36

x = 18 mph

y = 23 - 18 = 5 mph