Answer:
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
