Let the speed of the fish be F and the speed of the current be C.
When swimming upstream, the effective speed is F - C. Therefore, 12 = (F - C) * 4.
When swimming downstream, the effective speed is F + C. Therefore, 12 = (F + C) * 3.
Now we can solve these two equations simultaneously:
4F - 4C = 12,
3F + 3C = 12.
Dividing both equations by 4 and 3 respectively, we get:
F - C = 3,
F + C = 4.
Adding these two equations together, we get:
2F = 7,
F = 3.5 miles per hour.
Substitute F back into F - C = 3 to get:
3.5 - C = 3,
C = 0.5 miles per hour.
Therefore, the rate of the current is 0.5 miles per hour, option A.
A fish swims 12 miles upstream in 4 hours. The return trip takes only 3 hours. Find the rate of the current.
Answer options with 5 options
A.
0.5 miles per hour
B.
1 mile per hour
C.
4 miles per hour
D.
2 miles per hour
E.
3 miles per hour
1 answer
1 answer