Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - General Questions (Q.No. 4)
4.
Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 23 seconds. The ratio of their speeds is:
Answer: Option
Explanation:
Let the speeds of the two trains be x m/sec and y m/sec respectively.
Then, length of the first train = 27x metres,
and length of the second train = 17y metres.
 |
27x + 17y | = 23 |
| x+ y |
27x + 17y = 23x + 23y
4x = 6y
| |
x | = | 3 | . |
| y | 2 |
Discussion:
238 comments Page 24 of 24.
SAURABH PANDEY said:
1 year ago
Very well done. Thanks.
(7)
Thavapriya A said:
12 months ago
How to solve the following step?
27x+17y =23x+23y.
Could anyone tell me please?
27x+17y =23x+23y.
Could anyone tell me please?
(22)
Dripta Majumdar said:
11 months ago
Why is the length of the platform not taken into consideration? Anyone, please explain to me.
(10)
Anome said:
7 months ago
Very useful. Thanks all.
(10)
ARUN said:
6 months ago
I do not understand this. Please explain to me.
(7)
Student said:
6 months ago
A train takes 27 sec to reach man and 23 sec to cross train B, so the difference is 4 sec
B train takes 17 sec to reach the man and 23 sec to cross train A, so the difference is 6 sec.
Speed is inversely proportional to time, so the ratio of speed is 6:4.
So 3:2 is the answer.
B train takes 17 sec to reach the man and 23 sec to cross train A, so the difference is 6 sec.
Speed is inversely proportional to time, so the ratio of speed is 6:4.
So 3:2 is the answer.
(102)
Venkatesh said:
5 months ago
Let speeds be x and y.
Then, l1 = x * 27.
l2 = y * 17.
Time taken to cross each other = 23 seconds.
=> (l1+l2)/(x+y) = 23 seconds.
=> 27x + 17y = 23x + 23y.
=> x : y = 3:2.
Then, l1 = x * 27.
l2 = y * 17.
Time taken to cross each other = 23 seconds.
=> (l1+l2)/(x+y) = 23 seconds.
=> 27x + 17y = 23x + 23y.
=> x : y = 3:2.
(9)
Konatham preetham said:
1 month ago
@All.
You can solve alligation like take right side top 27 left side top take 17 middle of the alligation is 23 (17-23 = 6) and (27-23 = 4) and 2:3 inversely proportion 3:2 So, you can solve like only same like sec or km/hr or litres or kgs same terms you can solve like that.
You can solve alligation like take right side top 27 left side top take 17 middle of the alligation is 23 (17-23 = 6) and (27-23 = 4) and 2:3 inversely proportion 3:2 So, you can solve like only same like sec or km/hr or litres or kgs same terms you can solve like that.
(3)
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