Subject: General Aptitude · Chapter: Boats and Streams · Exam: · Marks: · Difficulty:
The speed of the boat in still water is 5 times that of the current, it takes 1.1 hours to row to point B form point A downstream. The distance between point A and point B is 13.2km. How much distance (in km) will it cover in 312 minutes upstream? [IBPS-Bank Spl. Officer (IT) Exam, 2015]
(a)43.2
(b)48
(c)41.6
(d)44.8
Answer
Answer (as printed): C
Explanation
Let the speed of the current be $x \mathrm{kmph}$. Then speed of the boat in still water $=5 x$ ∴ Downstream speed $=(5 x+x)=6 x \mathrm{kmph}$ Upstream speed $=(5 x-x)=4 x \mathrm{kmph}$ Now, $$\underset{\mathrm{A}}{\bullet} \quad \frac{13.2 \mathrm{km}}{\mathrm{B}}$$ According to the question, $$\begin{aligned} & & 1.1 \times 6 x & =13.2 \\ \Rightarrow & & 6.6 x & =13.2 \end{aligned} \Rightarrow x=\frac{13.2}{6.6}$$ $\therefore x=2 \mathrm{kmph}$ ∴ Upstream speed $=4 x=4 \times 2=8 \mathrm{kmph}$ $\therefore 312$ minutes $=5 \frac{1}{5}$ hours $=\frac{26}{5}$ hours ∴ Required distance travelled upstream = Speed × Time $$=8 \times \frac{26}{5}=41.6 \mathrm{km}$$