Aptitude - Problems on Trains - Discussion
Discussion Forum : Problems on Trains - Data Sufficiency 1 (Q.No. 3)
Directions to Solve
Each of the questions given below consists of a statement and / or a question and two statements numbered I and II given below it. You have to decide whether the data provided in the statement(s) is / are sufficient to answer the given question. Read the both statements and
- Give answer (A) if the data in Statement I alone are sufficient to answer the question, while the data in Statement II alone are not sufficient to answer the question.
- Give answer (B) if the data in Statement II alone are sufficient to answer the question, while the data in Statement I alone are not sufficient to answer the question.
- Give answer (C) if the data either in Statement I or in Statement II alone are sufficient to answer the question.
- Give answer (D) if the data even in both Statements I and II together are not sufficient to answer the question.
- Give answer(E) if the data in both Statements I and II together are necessary to answer the question.
3.
What is the length of a running train? | |
I. | The train crosses a man in 9 seconds. |
II. | The train crosses a 240 metre long platform in 24 seconds. |
Answer: Option
Explanation:
| Time taken by train to cross a man = | Length of train |  Speed = |
l | ....(i) |
| Speed of train | 9 |
| Time taken by train to cross a platform = |
(Length of train + Length of platform) |
Speed = |
l + 240 | ....(ii) |
| Speed of train | 24 |
| From (i) and (ii), we get | l | = | l + 240 | . |
| 9 | 24 |
Thus, l can be obtained. So both I and II are necessary to get the answer.
The correct answer is (E).
Discussion:
16 comments Page 1 of 2.
Ambika said:
1 decade ago
Ambika
Please any help me; I can't understand how it is possible , because here they didn't give any comment about speed . How can we equate both speeds (Man &Train). I think option D is correct. Anybody can understood please explain to me.
Please any help me; I can't understand how it is possible , because here they didn't give any comment about speed . How can we equate both speeds (Man &Train). I think option D is correct. Anybody can understood please explain to me.
Viresh said:
1 decade ago
Here same train is crossing both man n d platform so d speed ll b same in both d cases so optn E is correct
Prerana said:
1 decade ago
Speed of man is not mentioned. What if he is also moving with some speed. So answer should be D.
Yogitha said:
1 decade ago
Please give some instruction about train problems?
Linux said:
1 decade ago
Can you please explain what the answer to the equation is I chose option B on the premise that the length of the train is 10 m.
How would we solve the equation please?
How would we solve the equation please?
Ajay said:
1 decade ago
The speed of the train is given but nothing is mentioned about the speed of the man.
How can it be solved unless condition about the man is given?
How can it be solved unless condition about the man is given?
Nithyasri said:
1 decade ago
It's possible? I can't get it. Anyone else explain it.
(1)
Babu said:
1 decade ago
Train is passing a man.
Obviously the length of train will be the same as the required distance to pass that man as man has no length.
9 sec to pass the man (given).
24 sec to travel 240 m (given).
So, speed = 240/24 = 10 m/s.
Hence, Length of train = Distance travelled in 9s = 9*10 = 90 m.
Obviously the length of train will be the same as the required distance to pass that man as man has no length.
9 sec to pass the man (given).
24 sec to travel 240 m (given).
So, speed = 240/24 = 10 m/s.
Hence, Length of train = Distance travelled in 9s = 9*10 = 90 m.
(2)
Hernando said:
10 years ago
Answer should be D. No reason to assume the same speed of the train in both cases.
(1)
Nadeem said:
8 years ago
How 1st statement is true? Explain.
(1)
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