Question

A man can row a boat in still water at a speed of 5m/s. he covers a stretch of 200 metre in a river downstream during high and low tides in 10 sec and 25 sec respectively. what is the ratio of the speed(in m/s)of the water flowing in the river during high and low tides?

Answer 1

Ans = 5:1

Explanation -

Distance =200

Speed of still boat =5 m/s

Now ,

200/(5+x)= 10 sec

200 = 50 +10x

200-50 =10x

150 =10x

15 = x

So x =15 m/s

Similarly

200/(5+y) = 25m/s

200 = 125 +25y

75= 25y

3=y

So , y=3

Ratio of x and y(speed of stream )

15:3

5:1