Aptitude - Time and Distance - Discussion
Discussion Forum : Time and Distance - 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.
Two cars pass each other in opposite direction. How long would they take to be 500 km apart? | |
I. | The sum of their speeds is 135 km/hr. |
II. | The difference of their speed is 25 km/hr. |
Answer: Option
Explanation:
I gives, relative speed = 135 km/hr.
 Time taken = |
500 | hrs. |
| 135 |
II does not give the relative speed.
I alone gives the answer and II is irrelevant.
Correct answer is (A).
Discussion:
8 comments Page 1 of 1.
Dibya said:
2 years ago
@Barfi.
If both vehicles move in the same direction then it will take 20hr, for a 500 km distance between both vehicles.
(Because one vehicle is 25km faster than the other).
If both vehicles move in opposite directions then relative speed comes into play.
The distance between vehicles in one HR will be 135km. 500/135 = approx 3.7 hr.
If both vehicles move in the same direction then it will take 20hr, for a 500 km distance between both vehicles.
(Because one vehicle is 25km faster than the other).
If both vehicles move in opposite directions then relative speed comes into play.
The distance between vehicles in one HR will be 135km. 500/135 = approx 3.7 hr.
Tushar said:
3 years ago
How should we supose to know that sum is relative speed?
(2)
Shaheen said:
8 years ago
Thanks a lot.
Mahendar said:
8 years ago
Yes, you are correct @Vini.
Aaju said:
9 years ago
Agree with you @Vini.
Barfi said:
1 decade ago
As their difference of speed is given we can calculate their separation if they are moving in same direction. 500/25 = 20h.
So, option three is 100% correct.
So, option three is 100% correct.
(1)
Vini said:
1 decade ago
Hi girish
if any two vehicles are moving in opposite direction
say, vehicle1= x km/ph
& vehicle2 = y km/ph
then their relative speed is= x- (-y) = x+y (i.e. indicates the sum, which u asked)
since y is opposite, thats y it is taken as negative sign.
and if the vehicles are moving in same direction
then there relative speeds are = x - (+y) , "y" being in the same direction
i.e. = (x-y) km/ph
if any two vehicles are moving in opposite direction
say, vehicle1= x km/ph
& vehicle2 = y km/ph
then their relative speed is= x- (-y) = x+y (i.e. indicates the sum, which u asked)
since y is opposite, thats y it is taken as negative sign.
and if the vehicles are moving in same direction
then there relative speeds are = x - (+y) , "y" being in the same direction
i.e. = (x-y) km/ph
(1)
Girish paliwal said:
1 decade ago
How can the difference of their speed is not relative speed, & sum of their speeds are relative, it is possible they move in opp. Direction or may be one move one direction or another move in different direction.
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