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 6 of 21.
Mukesh Singh said:
1 decade ago
Sorry Dear...
But I found sentence mistake is this Qs.
If in Qs it is asked that speed is reduced to 200km/hr then given solution is right.
But in qs it asked that speed is reduced by, so soln should be
600/(t+1/2) = 200
t = 5/2 hr
But I found sentence mistake is this Qs.
If in Qs it is asked that speed is reduced to 200km/hr then given solution is right.
But in qs it asked that speed is reduced by, so soln should be
600/(t+1/2) = 200
t = 5/2 hr
Rahul said:
1 decade ago
very very easy question
distance 600 km.
suppose aircraft speed is 600km/hr
time =600/600=1hr
ans=1hr
check method=speed decreasing 200km/h
speed is 400km/h distance 600
600/400=1.5=======30 mint late original duration is 1 hr..ans
distance 600 km.
suppose aircraft speed is 600km/hr
time =600/600=1hr
ans=1hr
check method=speed decreasing 200km/h
speed is 400km/h distance 600
600/400=1.5=======30 mint late original duration is 1 hr..ans
Abhishek rohan said:
8 years ago
In question avg speed given:
The avg speed= total distance/total time elapsed
So according to question the equation becomes:
1200/2t - 200 =1200/(2t+1/2).
After solving,
4t^2+t-3=0,
(4t+3)(t-1)=0,
so t=1;(taking positive value).
The avg speed= total distance/total time elapsed
So according to question the equation becomes:
1200/2t - 200 =1200/(2t+1/2).
After solving,
4t^2+t-3=0,
(4t+3)(t-1)=0,
so t=1;(taking positive value).
Tanshi said:
8 years ago
600/x = 1200/2x+1+200.
600/x = 1200+(2x+1)(200)/2x+1 (for whole 2x+1).
600/x = 1200+400x+200/2x+1 (for whole 2x+1).
2x+1(600) = x(1200+400x+200).
1200x+600 = 1200x+400x^2+200x (cancel 1200x on bboth sides).
So 400x^2+200x-600.
600/x = 1200+(2x+1)(200)/2x+1 (for whole 2x+1).
600/x = 1200+400x+200/2x+1 (for whole 2x+1).
2x+1(600) = x(1200+400x+200).
1200x+600 = 1200x+400x^2+200x (cancel 1200x on bboth sides).
So 400x^2+200x-600.
Devendra said:
9 years ago
Dear all.
I think ,duration of the flight is 1.5 hour.
With the calculations, normal speed = 600 km/hr.
So reduced speed = 600 - 200 = 400 km/hr.
To cover the journey of 600 km @ 400 km/hr time taken = 600/400 = 1.5 hour.
I think ,duration of the flight is 1.5 hour.
With the calculations, normal speed = 600 km/hr.
So reduced speed = 600 - 200 = 400 km/hr.
To cover the journey of 600 km @ 400 km/hr time taken = 600/400 = 1.5 hour.
Manikanta said:
10 years ago
In this question I have a doubt its average speed for the trip was reduced by 200 km/hr i.e., trip means both upside and downside distance. Such that the distance is 1200 km (600 km for upside and 600 km for downside).
S. M said:
7 years ago
@All.
The Original duration or the duration it has taken? Confused by the answer.
I think original duration is 1 hour but it has taken 30 mins more due to bad weather. Am I right?
Please anyone explain me.
The Original duration or the duration it has taken? Confused by the answer.
I think original duration is 1 hour but it has taken 30 mins more due to bad weather. Am I right?
Please anyone explain me.
Nandasena said:
1 decade ago
It is said that average speed is reduced by 200. Not just speed is reduced by 200. Then we know there is another equation to calculate average speed. But in here it has not used. Can someone please explain?
Kannan said:
8 years ago
Distance=600km
Speed=200km
Time=x+30mins
So we have to the time duration,
Time = Distance/speed.
x+30=600/200,
x+30=3,
x=3-30,
x=27mins(neglect the negative),
x=27+30min,
x=57 mins(Almost 1hr),
Ans x=1hr.
Speed=200km
Time=x+30mins
So we have to the time duration,
Time = Distance/speed.
x+30=600/200,
x+30=3,
x=3-30,
x=27mins(neglect the negative),
x=27+30min,
x=57 mins(Almost 1hr),
Ans x=1hr.
Karthik said:
1 decade ago
(600/x)-600/(x+1/2)=200
(600/x)-600*2/(2x+1)=200
take LCM we will get
(600(2x+1)-600*2*x)/x*(2x+1)=200
600(2x+1)-600*2*x=200*x*(2x+1)
600(2x+1)-200*x*(2x+1)=600*2*x
i think now it ll b easy to simply
(600/x)-600*2/(2x+1)=200
take LCM we will get
(600(2x+1)-600*2*x)/x*(2x+1)=200
600(2x+1)-600*2*x=200*x*(2x+1)
600(2x+1)-200*x*(2x+1)=600*2*x
i think now it ll b easy to simply
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