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 21 of 21.
Shyam kumar said:
1 year ago
D = S * T.
600 = 200 * (T+30),
600/200 = T+30.
T = 27.
TOTAL DURATION = T+30= 27+30 = 57 ~1HOUR.
600 = 200 * (T+30),
600/200 = T+30.
T = 27.
TOTAL DURATION = T+30= 27+30 = 57 ~1HOUR.
(101)
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)
Parvezkhan Pathan said:
1 year ago
Let, The speed of flight is:xkm/hr.
The total distance travelled by flight is = 600km
The speed is reduced to = x - 200km/hr,
Time was taken with speed x = 600/x.
Similarly,
Time taken by flight with reduced speed = 600/(x-200)
By Given Condition,
(600/x) + 1/2 = 600/(x-200)
1200 + x/2x = 600/(x-200)
(x-200) * (1200+x) = 1200x
So, x^2 - 200x - 240000 = 0,
(x+400) * (x - 600) = 0,
So x = 600.
Time taken is = 600/600 = 1hr.
The total distance travelled by flight is = 600km
The speed is reduced to = x - 200km/hr,
Time was taken with speed x = 600/x.
Similarly,
Time taken by flight with reduced speed = 600/(x-200)
By Given Condition,
(600/x) + 1/2 = 600/(x-200)
1200 + x/2x = 600/(x-200)
(x-200) * (1200+x) = 1200x
So, x^2 - 200x - 240000 = 0,
(x+400) * (x - 600) = 0,
So x = 600.
Time taken is = 600/600 = 1hr.
(21)
Moustafa Ehosiny said:
1 year ago
D=600 Km,
S=200 Km/hr
Let initial speed be x.
So, new speed = x-200Km/hr
S = D/T, T=D/S.
So, T= 600/ x-200.
x-200 = 600
x = 800
T = 600/800-200 = 600/600 = 1 hour.
S=200 Km/hr
Let initial speed be x.
So, new speed = x-200Km/hr
S = D/T, T=D/S.
So, T= 600/ x-200.
x-200 = 600
x = 800
T = 600/800-200 = 600/600 = 1 hour.
(324)
Circle said:
12 months ago
The speed of the second train =400/4 = 100km/h.
Distance is same in both cases:
Then,
The ratio of speed = reverse ratio of time
7/8 = 8/7.
Speed of first train = 100/8/7= 87.5km/h.
Distance is same in both cases:
Then,
The ratio of speed = reverse ratio of time
7/8 = 8/7.
Speed of first train = 100/8/7= 87.5km/h.
(12)
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