Aptitude - Time and Distance - Discussion
Discussion Forum : Time and Distance - General Questions (Q.No. 6)
6.
In a flight of 600 km, an aircraft was slowed down due to bad weather. Its average speed for the trip was reduced by 200 km/hr and the time of flight increased by 30 minutes. The duration of the flight is:
Answer: Option
Explanation:
Let the duration of the flight be x hours.
| Then, | 600 | - | 600 | = 200 |
| x | x + (1/2) |
 |
600 | - | 1200 | = 200 |
| x | 2x + 1 |
x(2x + 1) = 3
2x2 + x - 3 = 0
(2x + 3)(x - 1) = 0
x = 1 hr. [neglecting the -ve value of x]
Discussion:
205 comments Page 1 of 21.
Zary said:
2 decades ago
Hi frnds! I'm not getting why you are taking.
600 - 600 = 200.
X x + (1/2) ?
Please explain in detail!
600 - 600 = 200.
X x + (1/2) ?
Please explain in detail!
Nirmal.s said:
2 decades ago
Am also having de same doubt yaar.
Lathesh said:
2 decades ago
Need more detailed explanation.
Kiran.p said:
2 decades ago
We know that speed=distance/time;
Let us assume time as x,then actual speed=600/x;
Now the time is incremented to 30 min right,
So, now the speed=600/(x+1/2)
Here we take the time in hrs so (x+1/2).
In the problem the speed is reduced by 200km/hr
So the diff btwn speed is equal to 200km/hr.
i.e. 600/x-600/x+(1/2)=200
Let us assume time as x,then actual speed=600/x;
Now the time is incremented to 30 min right,
So, now the speed=600/(x+1/2)
Here we take the time in hrs so (x+1/2).
In the problem the speed is reduced by 200km/hr
So the diff btwn speed is equal to 200km/hr.
i.e. 600/x-600/x+(1/2)=200
(2)
Sundarraj said:
2 decades ago
Thanks Kiran. Your answer is very easy to grasp.
Sundar raj said:
2 decades ago
@Kiran
your answer is right only. But can you briefly explain how to find the value X from 2x2 + x - 3 = 0.
your answer is right only. But can you briefly explain how to find the value X from 2x2 + x - 3 = 0.
Bhavana said:
2 decades ago
2x2 + x - 3 = 0.
2x2 - 2x + 3x - 3 = 0.
2x(x - 1) + 3(x- 1) = 0.
(2x + 3) (x - 1) = 0.
X=3/2 or x=1.
Hope you got d answer Sundar.
2x2 - 2x + 3x - 3 = 0.
2x(x - 1) + 3(x- 1) = 0.
(2x + 3) (x - 1) = 0.
X=3/2 or x=1.
Hope you got d answer Sundar.
Sivaram said:
1 decade ago
Hi Bhavana, I can't get the answer why you got 1/2. How you get it?
Neelima said:
1 decade ago
60 mins = 1 hr
Then, 30 mins = 1/2 hr.
Then, 30 mins = 1/2 hr.
Sivakumaran said:
1 decade ago
X (2x + 1) = 3.
How this step comes along.
How this step comes along.
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