Miscellaneous Question 17
- The speed of a boat in still water is $15 $ $kmph$ and the speed of the current is $3$ $ kmph$. The distance travelled by the boat from point A to point $B$ downstream is $24 $ $km$ more than the distance covered by the same boat from point $B$ to point $C$ upstream in the same time. How much time will the boat take to travel from point $C$ to point B downstream?
(1) $2$ hrs
(2) $2$ hrs $30$ mins
(3) $2$ hrs $40$ mins
(4) $2$ hrs $10$ mins
(5) $3$ hrs $20$ mins
(IBPS Specialist Officer (IT) CWE 14.02.2016)
Show Answer
Correct Answer: 17. (3)
Solution: 17. (3) Rate downstream of boat
$=15+3=18$ $ \mathrm{kmph}$
Rate upstream of boat
$=15-3=12 $ $\mathrm{kmph}$
Let, $\mathrm{BC}=x \mathrm{km}$
$\therefore \mathrm{AB}=(x+24) \mathrm{km}$
According to the question,
$\frac{x+24}{18}=\frac{x}{12}$
$\Rightarrow \frac{x+24}{3}=\frac{x}{2}$
$\Rightarrow 3 x=2 x+48 \Rightarrow 3 x-2 x=48$
$\Rightarrow x=48 $ $\mathrm{km}$.
Time taken in rowing $48$ $ \mathrm{km}$ downstream $=\frac{48}{18}$ hours
$=\frac{8}{3}$ hours $=2$ hours $\frac{2}{3} \times 60$ minutes
$=2$ hours 40 minutes
BETA
