There is a river whose speed of a flow is 3 m/s.
A ship which moves at the speed of 5 m/s with no flow leaves A point downriver and goes up to upriver B point.
The ship returns immediately at B point to A point.
After leaving until coming back to A point, it took 3 minutes and 20 seconds.
Find the distance of between A point and B point.
Answer
320m
Solution
The speed ratio of going up and down of this ship is (5 - 3) : (5 + 3) = 1 : 4.
Thus, the time ratio of up and down is = 4 : 1.
The time of going down is 200 minutes × 1/(1 + 4) = 40 minutes.
Therefore, the distance of A point and B point is 8 m/m × 40 minutes = 320 m.
A ship which moves at the speed of 5 m/s with no flow leaves A point downriver and goes up to upriver B point.
The ship returns immediately at B point to A point.
After leaving until coming back to A point, it took 3 minutes and 20 seconds.
Find the distance of between A point and B point.
Answer
320m
Solution
The speed ratio of going up and down of this ship is (5 - 3) : (5 + 3) = 1 : 4.
Thus, the time ratio of up and down is = 4 : 1.
The time of going down is 200 minutes × 1/(1 + 4) = 40 minutes.
Therefore, the distance of A point and B point is 8 m/m × 40 minutes = 320 m.
