Home › IBPS RRB › Quantitative Aptitude › Boats and Streams › A man rows at 8 km/h in still water. The current…
A man rows at 8 km/h in still water. The current is 2 km/h and a round trip to a place and back takes 2 hours. How far is the place?
A8 km
B6 km
C7.5 km
D9 km
Answer & Solution
Correct answer: C. 7.5 km
1. Downstream speed = 8 + 2 = 10 km/h; upstream speed = 8 − 2 = 6 km/h.
2. For distance d: d/10 + d/6 = 2 ⇒ (3d + 5d)/30 = 2 ⇒ 8d = 60.
3. d = 60/8 = **7.5 km**. (Choosing 8 km ignores the unequal up/down speeds.)
_Source: IBPS RRB Officer Scale I Prelims PYQ (Examrace), Q.62_
Related questions
A car uses 4 litres of petrol for 60 km. Its mileage in km per litre is:A man covers a distance in 6 hours at 40 km per hour. To cover it in 4 hours he must traveA man travels equal distances at 40 km per hour and at 60 km per hour. His average speed iA train 200 m long crosses a 100 m platform at 36 km per hour. It takes:A train 150 m long runs at 54 km per hour. The time it takes to pass a pole is:A car covers 300 km at 50 km per hour. At 75 km per hour the same trip would take:Zaheeda doubles her speed on the same route. The time she takes:A journey takes 120 km at a steady 60 km per hour. The time taken is: