In this problem, 2 equations could be formed.
The distance would be equal in either direction which is 192 miles. They would differ in speed and time.
let x= speed of current and y = speed of still water
Downstream: 8(x + y) = 192 ---> eq 1
Upstream: 24(x - y) = 192 ---> eq 2
Simplifying,
eq 1: x + y = 24
eq 2: x - y = 8
x + y = 24
-
x - y = 8
------------------
2y = 16
y = 8
Then,
x + 8 = 24
x = 16
The answer is
speed of still water = 8 mph
speed of current = 16 mph