A man takes 3 hours 45 minutes to row a boat 25 km downstream of a river and 2 hours 30 minutes to cover a distance of 15 km upstream. Find the speed of the current.
Choose the correct choice from the following
A) 1 km/hr
B) 2/3 km/hr
C) 1/3 km/hr
D) 4 km/hr
E) None of these
Explanation:   First of all, we know that   speed of current = 1/2(speed downstream - speed upstream) [important]   So we need to calculate speed downstream and speed upstream first.   Speed = Distance / Time [important]   Speed upstream =(25/3 3/4)km/hr   =20/3km/hr   Speed Downstream = (15/2 1/2)km/hr   =6km/hr   So speed of current = 1/2(20/3−6)   =1/3 km/hr   Option 1/3 km/hr
<result>C</result>
A man takes 3 hours 45 minutes to row a boat 25 km downstream of a river and 2 hours 30 minutes to cover a distance of 15 km upstream. Find the speed of the current.