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:
206 comments Page 5 of 21.
Vijaya lakshmi said:
6 years 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 between 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 between speed is equal to 200km/hr.
i.e. 600/x-600/x+(1/2) = 200.
(3)
Esha said:
6 years ago
How do we get x(2x + 1) = 3? please explain.
(1)
Sami said:
7 years ago
Speed = distance/time.
Time = distance/speed.
Speed=600-200 = 400 km/hr.
Distance to cover = 600 km.
Duration required(time) = 600/400 = 3/2 hr.
3/2*60 = 60 min = 1hr.
Time = distance/speed.
Speed=600-200 = 400 km/hr.
Distance to cover = 600 km.
Duration required(time) = 600/400 = 3/2 hr.
3/2*60 = 60 min = 1hr.
(4)
Anand Kumar said:
7 years ago
600/(x-200) - 30/60 =600/x ---> Eq.(1)
=> from equation (1) we get , x = 600.
Now, we have to find the duration of the flight = 600/x = 600/600 = 1hour. Answer.
=> from equation (1) we get , x = 600.
Now, we have to find the duration of the flight = 600/x = 600/600 = 1hour. Answer.
Meron said:
7 years ago
I am not getting this, please explain.
Kishor said:
7 years ago
Thank you @Bhavana and @Shanti.
Rahul sethupathi said:
7 years ago
Distance = speed/time.
=200/(30/60) by 30 min is converted into hour.
= 400 km.
Time= distance/speed.
= 400/400 km/kmhr.
= 1 hr.
=200/(30/60) by 30 min is converted into hour.
= 400 km.
Time= distance/speed.
= 400/400 km/kmhr.
= 1 hr.
Mamatha said:
7 years ago
After solving the equation x has two values 1 and 3/2. Why only 1 has taken as answer?
Ashutosh said:
7 years ago
How to find LCM of x and 2x+1?
Yuva said:
7 years ago
Thanks @Saravana Gopi.
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