Miscellaneous Question 32
- A boat running downstream covers a distance of $30$ $ km$ in 2 hours. While coming back the boat takes 6 hours to cover the same distance. What is the speed of that boat in still water ? (in $km / h$ )
(1) 15
(2) 5
(3) 10
(4) 20
(5) None of these
(Indian Bank PO (Pre.) Exam, 21.01.2017 (2nd Sitting))
Show Answer
Correct Answer: 32. (3)
Solution:
- (3) Rate downstream of boat
$=\frac{30}{2}=15$ $ \mathrm{kmph}$
Rate upstream
$=\frac{30}{6}=5$ $ \mathrm{kmph}$
$\therefore$ Speed of boat in still water
$=\frac{1}{2}$ (rate downstream + rate upstream)
$=\frac{1}{2}(15+5 \mathrm{kmph})=10 $ $\mathrm{kmph}$
BETA
