A man rows 750 m in 675 seconds against the stream and returns

A man rows 750 m in 675 seconds against the stream and returns in 7 1 minutes.
2
Find his rowing speed in still water.

Let the speed of man in still water be p kmph and rate of stream be q kmph

∴ Distance =	750	km =	3	km
	1000		4

Time = 675 seconds

Time =	675	= 11	1	minutes
	60		4

p - q =	3	=	1	km / min
	45		15

p + q =	3	×	2	=	1	km/min
	4		15		10

∴ Speed in still water =	1		1	+	1		=	1		3 + 2
	2		10		15			2		30

Speed in still water =	1	km/min
	12

Speed in still water =	1	× 60 kmph = 5 kmph
	12

Using the given formula :

p =	750	×	2 × 60
	1000		15

p = 6 km/hr

q =	750m
	675 min

q =	750	×	3600	= 4hrs
	1000		675

Speed of Boat =	1	(p + q)
	2

Speed of Boat =	1	(6 + 4) = 5 km/hrs
	2

A man rows 750 m in 675 seconds against the stream and returns in 7	1	minutes.
	2