Respuesta :
Answer: the speed of the still boat is 14 mph
Step-by-step explanation:
Let x represent the speed of the still boat.
A person travels 8 miles down a stream. Assuming he travels with the current and if the current of the river is 2 mph, it means that the total speed is (x + 2) mph
Time = distance/time
Time spent in travelling with the current is
8/(x + 2)
In the same time they can travel 6 miles upstream. Assuming he travels against the current, it means that the total speed is (x - 2) mph
Time = distance/time
Time spent in travelling against the current is
6/(x - 2) .since the time is the same, then
8/(x + 2) = 6/(x - 2)
Cross multiplying, it becomes
8(x - 2) = 6(x + 2)
8x - 16 = 6x + 12
8x - 6x = 12 + 16
2x = 28
x = 28/2
x = 14
