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 9 of 21.
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.
AnilKumarReddy said:
10 years ago
When solving the equation 2x^2+x-3 = 0.
We get two factors for x = 1 and x = -3/2.
Here time is always positive. So we are taking x = 1 there is no logic.
We get two factors for x = 1 and x = -3/2.
Here time is always positive. So we are taking x = 1 there is no logic.
Nitu said:
4 years ago
600/x - 1200/2x+1 = 200.
Lcm is
You get (2x+1)(600) - 1200x = 200(2x^2 +x).
1200x+600-1200x = 200(2x^2 +x),
600/200(2x^2+1),
3/(2x^2+x),
2x^2+x = 3.
X = 1.
Lcm is
You get (2x+1)(600) - 1200x = 200(2x^2 +x).
1200x+600-1200x = 200(2x^2 +x),
600/200(2x^2+1),
3/(2x^2+x),
2x^2+x = 3.
X = 1.
(8)
Azly said:
10 years ago
Friends, we have to use trigonometry to solve this problems. And why they have mentioned average speed is reduced by 200 km/h since it the reduced "speed".
Nitin Kataria said:
2 years ago
New speed (old speed - change in speed) = ΔS/ΔT.
200/.5h = 400km/h.
new time(old time + extra time) = 600/400 = 1.5h,
Initial time is taken 1.5 - 0.5 = 1h.
200/.5h = 400km/h.
new time(old time + extra time) = 600/400 = 1.5h,
Initial time is taken 1.5 - 0.5 = 1h.
(43)
Arun said:
7 years ago
If the average speed is increased by 200km/hr and time of flight is decreased by 30mins. What is the equation?
(600/x)-(600/x+1/2))=-200 is this correct?
(600/x)-(600/x+1/2))=-200 is this correct?
Shakila said:
1 decade ago
I agree to @Deepak Jain's word and yes bad weather has it be considered and as tony mentioned 400 is the speed.
Its just simple as much as 1.5 hours.
Its just simple as much as 1.5 hours.
Sridhar reddy said:
1 decade ago
One more similar method.
Let x be the speed
600/(x-200) - 600/x = 30/60(in hrs)
solving we get x=600
then Time taken= distance/speed = 600/600 =1hr
Let x be the speed
600/(x-200) - 600/x = 30/60(in hrs)
solving we get x=600
then Time taken= distance/speed = 600/600 =1hr
Sivanityam said:
1 year ago
D = 600km.
Average speed is 200km/hr,
s = 600/3 = 200km/hr.
200km time taken 30min.
The remaining time is 400km = 30 + 30 = 60min = time taken = 1hr.
Average speed is 200km/hr,
s = 600/3 = 200km/hr.
200km time taken 30min.
The remaining time is 400km = 30 + 30 = 60min = time taken = 1hr.
(80)
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)
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