Ratio And Proportion Ques 41
Question-
The sum of the lengths of two trains A and $B$ is 660 metre. The ratio of the speeds of $A$ and $B$ is $5: 8$. The ratio between time to cross an electric pole by $A$ and $B$ is $4: 3$. Find the difference in the length of two trains? (in metre)
(1) 50
(2) 60
(3) 80
(4) 75
(5) 90
(IBPS Bank PO/MT CWE-VII (Prelim Exam) 15.10.2017)
Show Answer
Correct Answer: (2)
Solution: (2)
Length of train A $=x$ metre
$\therefore$ Length of train B $=(660-x)$ metre
When a train crosses a pole, it covers distance equal to its length.
$\therefore \frac{\frac{x}{4}}{\frac{660-x}{3}}=\frac{5}{8}$
$\Rightarrow \frac{3 x}{4(660-x)}=\frac{5}{8}$
$\Rightarrow \frac{3 x}{660-x}=\frac{5}{2}$
$\Rightarrow 6 x=3300-5 x$
$\Rightarrow 11 x=3300$
$\Rightarrow x=\frac{3300}{11}=300$ metre
$\therefore$ Length of train B $=360$ metre
$\therefore$ Required difference $=(360-300)$ metre $=60$ metre
BETA
