A man can row a boat in still water at a speed of 5 m/s. He covers a stretch of 200 m in a river downstream during high and low tides in 10 s and 25 s respectively. What is the ratio of the speed (in m/s) of the water flowing in the river during high and low tides?
Answer & explanation
Correct answer: option 2
We know that,
Speed = \(\frac{ Distance}{ time}\)
Let the speed of high and low tides be a and b
The speed of boat in high tide (downstream) = a + 5
= a + 5 = \(\frac{200}{10}\)
= b + 5 = 20
= a = 15 m/sec
Similarly, y + 5 = \(\frac{200}{25}\)
= y = 3 m/sec
So,The ratio of the speed of the water flowing in the river during high and low tides = 15 : 3 = 5 : 1