A man takes 3 hours 45 minutes to row a boat 15 km downstream of a river and 2hours30minutes to cover a distance of 5km upstream. find the speed of the river current in km/hr.  Options.
A) 2km/hr	B) 1km/hr	C) 5km/hr	D) 2m/hr	E) 4km/hr
rate downstream=(15/3 ¾)km/hr=(15*4/15)km/hr=4km/hr.   Rate upstream=(5/2 ½)km/hr=(5*2/5)km/hr=2km/hr.   Speed of current=1/2(4-2)km/hr=1km/hr   Answer is 1km/hr.
<result>B</result>
A man takes 3 hours 45 minutes to row a boat 15 km downstream of a river and 2hours30minutes to cover a distance of 5km upstream. find the speed of the river current in km/hr.