Speed of a boat is 5 km per hour in still water and the

Speed of a boat is 5 km per hour in still water and the speed of the stream is 3 km per hour. If the boat takes 3 hours to go to a place and come back, the distance of the place is :

Here , Speed of a boat in still water = 5 km per hour and the speed of the stream = 3 km per hour.
Let the required distance be d km, then

	d	+	d	= 3
	5 + 3		5 - 3

	d	+	d	= 3
	8		2

⇒	d + 4d	= 3
	8

⇒ 5 d = 24

⇒ d =	24	= 4.8 km
	5

Using the given formula :
Here, p = 5, q = 3, t = 3

d =	t(p² - q²)
	2p

d =	3(5² - 3²)	=	3 × 16	= 4.8 km
	2 × 5		10