A man can row at a speed of 41km/hr in still water. If

A man can row at a speed of 4 1 km/hr in still water. If he takes 2 times
2
as long to row a distance upstream as to row the same distance downstream, then, the speed of stream (in km/hr) is

Let the speed of stream be x kmph

∴ Rate upstream =	9	- x
	2

Rate downstream =	9	+ x
	2

Then, According to question ,

⇒ 9 - 2x =	9	+ x
	2

⇒ 3x = 9 -	9	=	9
	2		2

⇒ x =	9	=	3	= 1.5 kmph
	2 × 3		2

Using the given formula :
Here, t₁ = 2k , t₂ = k

Speed of Boat =	9	kmph
	2

	Speed of Boat	=	t₁ + t₂
	Speed of Stream		t₁ - t₂

	9	=	2k + k
	2 × Speed of Stream		2k - k

Speed of Stream = 1.5 km/hr

A man can row at a speed of 4	1	km/hr in still water. If he takes 2 times
	2