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 3 of 21.
Tony said:
4 years ago
Anyone, please explain from the 2nd Step.
Navin said:
4 years ago
@Saravanakgopi.
Thanks for simplifying the answer in detail.
Thanks for simplifying the answer in detail.
Ravi said:
4 years ago
S=D/T(30 min increased).
200 = 600/(x+30).
x+30 = 600/200,
x+30 = 3,
x = 27.
Time is always positive.
So, time increses by 30=x+30.
= 27 + 30 = 57 = 1hr.
200 = 600/(x+30).
x+30 = 600/200,
x+30 = 3,
x = 27.
Time is always positive.
So, time increses by 30=x+30.
= 27 + 30 = 57 = 1hr.
(24)
Yogi said:
4 years ago
Simple,
Here is a trick, for such question, always break distance in its multiple,
For e,g.
600km = 300kmph x 2 hour.
Or
600km = 600kmph x1 hour
So we can see for 300kmph it takes 2 hours and for 600kmph it takes 1 hour.
And that's the answer.
Here is a trick, for such question, always break distance in its multiple,
For e,g.
600km = 300kmph x 2 hour.
Or
600km = 600kmph x1 hour
So we can see for 300kmph it takes 2 hours and for 600kmph it takes 1 hour.
And that's the answer.
(10)
Varsh said:
4 years ago
Its simple only, take LCM of (600/x)-(1200/(2x+1)) = 200,
you get (2x+1)(600) - 1200x = 200(2x^2 +x),
2x^2 +x = 3.
which is nothing but x(2x+1) = 3.
you get (2x+1)(600) - 1200x = 200(2x^2 +x),
2x^2 +x = 3.
which is nothing but x(2x+1) = 3.
(3)
Harika said:
4 years ago
It's simple way using average model.
2 * X * Y/(X+Y) = 2 * 200 * 600/200 * 600.
=>2.
In 30minutes we have to find?
2 * 30minutes = 60minutes
60minutes is gone to 1hour.
Ans: 1hour.
2 * X * Y/(X+Y) = 2 * 200 * 600/200 * 600.
=>2.
In 30minutes we have to find?
2 * 30minutes = 60minutes
60minutes is gone to 1hour.
Ans: 1hour.
(3)
Gayathri said:
5 years ago
Can anyone explain in a simple method?
(1)
Priyanka said:
5 years ago
Can anyone explain in a simple way? please.
(1)
Patel said:
5 years ago
Here we get x=1, but the question is to find time duration of a plane in bad weather, which is x+0.5 hrs. So the answer must be 1.5hrs. Right?
(1)
Manish said:
5 years ago
Simple way to solve this problem:
Distance = speed * time.
Let the distance be d and the time taken by the plane at 600 km/hr be a
Then:
d=600*a (1) at regular speed
and, d=(600-200) * (a+.5 hr) (2) at reduced speed
Equating the two we get;
600*a = 400(a+.5)
600a = 400a + 200
200a=200
a=1.
The time taken is 1hr.
Distance = speed * time.
Let the distance be d and the time taken by the plane at 600 km/hr be a
Then:
d=600*a (1) at regular speed
and, d=(600-200) * (a+.5 hr) (2) at reduced speed
Equating the two we get;
600*a = 400(a+.5)
600a = 400a + 200
200a=200
a=1.
The time taken is 1hr.
(5)
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