Subject: General Aptitude · Chapter: Boats and Streams · Exam: 2015 · Marks: · Difficulty:
A man takes 2.2 times as long to row a distance upstream as to row the same distance downstream. If he can row 55 km downstream in 2 hours 30 minutes, what is the speed of the boat in still water?
(a)40 km/h
(b)8 km/h
(c)16 km/h
(d)24 km/h
Answer
Answer (as printed): C
Explanation
Speed of the boat in downstream $=\frac{55}{2.2}=\frac{55 \times 10}{2.5}=22 \mathrm{km} / \mathrm{h}$ Then, speed of the boat in upstream $$=\frac{22}{2.2}=\frac{22 \times 10}{22}=10 \mathrm{km} / \mathrm{h}$$ ∴ Speed of boat in still water $=\frac{22+10}{2}=16 \mathrm{km} / \mathrm{h}$