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:
211 comments Page 1 of 22.
Sagarika M said:
1 month ago
Flight travells 600kmph.
The speed reduced by 200kmph means 600-200=400kmph, so it was travelling at 400kmph.
Now, time taken to travel 400kmph is t+30min = t + 0.5hr.
=>s=d/t,
=>400kmph = 600km/t + 0.5hr.
=>400km/1hr = 600km/t + 0.5hr.
=>400km(t+0.5hr)= 600km(1hr).
=>2t + 1hr = 3hr.
=>2t = 3hr - 1hr.
=>t=1hr
The speed reduced by 200kmph means 600-200=400kmph, so it was travelling at 400kmph.
Now, time taken to travel 400kmph is t+30min = t + 0.5hr.
=>s=d/t,
=>400kmph = 600km/t + 0.5hr.
=>400km/1hr = 600km/t + 0.5hr.
=>400km(t+0.5hr)= 600km(1hr).
=>2t + 1hr = 3hr.
=>2t = 3hr - 1hr.
=>t=1hr
Shiva said:
4 months ago
Here we know that the avg speed is 200km/hr. So it mean actual speed is 400 km/hr now we can us time formula and the when we get the answer we have to add 30min. The answer is 60min =1 hr.
(5)
Miithun A said:
6 months ago
Given:
Distance = 600 km.
Speed reduced by = 200 km/hr.
Time increased by = 0.5 hr.
Let us assume;
Original time = 600/600 = 1 hr.
Reduced speed = 600 − 200 = 400 km/hr.
New time = 600/400 = 1.5 hr.
Distance = 600 km.
Speed reduced by = 200 km/hr.
Time increased by = 0.5 hr.
Let us assume;
Original time = 600/600 = 1 hr.
Reduced speed = 600 − 200 = 400 km/hr.
New time = 600/400 = 1.5 hr.
(15)
Shiv said:
10 months ago
Average speed = total distance/total time
Average speed = 200km/hr.
Total distance = 600km.
otal time = x+(x+30),
= 2x+30 min,
= 2x+30/60,
= 2x+1/2 hr.
And put these values into the formula.
200 = 600/2x + 1/2.
x = 1 hour.
Average speed = 200km/hr.
Total distance = 600km.
otal time = x+(x+30),
= 2x+30 min,
= 2x+30/60,
= 2x+1/2 hr.
And put these values into the formula.
200 = 600/2x + 1/2.
x = 1 hour.
(14)
Mahadeb Das said:
11 months ago
D = 600 Km,
S = 200 Km/hr
Let the 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 the 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.
(46)
Mohamed Niyas said:
1 year ago
Answer is 1.5hours.
(10)
Circle said:
2 years 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.
(17)
Moustafa Ehosiny said:
2 years 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.
(381)
Parvezkhan Pathan said:
2 years 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.
(29)
Sivanityam said:
2 years 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.
(97)
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