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:
233 comments Page 12 of 24.
Kriti said:
1 decade ago
How can the time be taken as the ratio for length?
I mean why 27x and 17y. 27 and 17 are time, then how can they be taken as ratios of length?
I mean why 27x and 17y. 27 and 17 are time, then how can they be taken as ratios of length?
Mallikrjunrao said:
9 years ago
In very simple method.
27 17
23
6 : 4
...................
3:2
..................
By using mixed alligation method.
27 17
23
6 : 4
...................
3:2
..................
By using mixed alligation method.
Prasanth said:
1 decade ago
Can anyone please tel me how x+y is came.
They asked to find speed of that we have to use speed = length\time only know but how x+y is came.
They asked to find speed of that we have to use speed = length\time only know but how x+y is came.
Shyam said:
7 years ago
T1=27-23=4,T2=23-17=6.
Speed=distance/time.
"Speed" inversely propotional to "time"
(S1/S2)=(T2/T1)=6/4=3/2,
S1:S2=3:2.
Speed=distance/time.
"Speed" inversely propotional to "time"
(S1/S2)=(T2/T1)=6/4=3/2,
S1:S2=3:2.
FATHIMA said:
1 decade ago
The 1st train sec 27-23=4.
The 2nd train sec 23-17=6.
So both are divide by 2.
4/2=2, and 6/3=3.
So the ratio is 3:2 its right method?
The 2nd train sec 23-17=6.
So both are divide by 2.
4/2=2, and 6/3=3.
So the ratio is 3:2 its right method?
Dheeraj said:
1 decade ago
Hi Lokesh,
Can you please explain why you've said 27x-24x=23y-17y.....?
I can't see figure of 24 ain't where???
Thanks in advance....
Can you please explain why you've said 27x-24x=23y-17y.....?
I can't see figure of 24 ain't where???
Thanks in advance....
Avinash said:
1 decade ago
First you have to know that mod(positive or negative value) = positive value
So mod(23-17)=6
mod(23-27)=mod(-4)=4
Hope you understood.
So mod(23-17)=6
mod(23-27)=mod(-4)=4
Hope you understood.
Anomoys said:
8 years ago
There is a difference of 27-17 = 10.
And we use 10 for subtracting.
in
4x = 6y
10-4x=10-6x.
Answer is 6x=4y.
x = 3 and y=2.
And we use 10 for subtracting.
in
4x = 6y
10-4x=10-6x.
Answer is 6x=4y.
x = 3 and y=2.
Divya. A said:
7 years ago
Here distance is not mentioned. But you took 27 and 17 as distance. How can we take time interms of distance? Can anyone please explain?
Smnk said:
9 years ago
Guys!
Difference between the 23s and 27s is 4 and,
Difference between the 23s and 17s is 6 of other train.
So, the ratio is 4 and 6.
Difference between the 23s and 27s is 4 and,
Difference between the 23s and 17s is 6 of other train.
So, the ratio is 4 and 6.
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