A man can row 7 ½ kmph in still water. If in a river running at 1.5 km/hr an hour, it takes him 50 minutes to row to a place and back, how far off is the place?

A. 2 km

B. 3 km

C. 4km

D. 5km

Correct Answer : B.

Speed downstream =(7.5+1.5)km/hr=9 km/hr;

Speed upstream=(7.5-1.5)kmph=6kmph.

Let the required distance be x km.then,

x/9+x/6=50/60.

2x+3x=(5/6*18)

5x=15

x=3.

Hence, the required distance is 3km.

Comment

a man can row 18 kmph in still water.it takes him thrice as long to row up as to row down the river.…
A man takes 3 hours 45 minutes to row a boat 15 km downstream of a river and 2hours30minutes to cover…
A man can row upstream at 7 kmph and downstream at 10kmph.find man’s rate in still water and the…
A man can row upstream at 8 kmph and downstream at 13 kmph. The speed of the stream is:
A boat man goes 2 km against the current of the stream in 1 hr and goes 1 km along the current in 10…
A man can row downstream 32 km and upstream 14 km. If he takes 6 hr to cover each distance , then the…
A man can row 40km upstream and 55km downstream in 13 hours also, he can row 30km upstream and 44km…
A boat running upstream takes 8 hrs 48 min to cover a certain distance , while it take 4 hrs to cover…
A man takes twice as long to row a distance against the stream as to row the same distance in…
A man can row three-quarters of a kilometre against the stream in 1114 min. The speed (in km/hr) of…
In one hour, a boat goes 11 km along the stream and 5 km against the stream. The speed of the boat in…
In a stream running at 2kmph,a motor boat goes 6km upstream and back again to the starting point in…
A boat running downstream covers a distance of 16 km in 2 hrs while for covering the same distance upstream…
A man can row 7 ½ kmph in still water. If in a river running at 1.5 km/hr an hour, it takes him…