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 10 of 21.
Sahin said:
9 years ago
@Rahim Shaikh.
There is a small mistake in your answer.
Tt will be:
(x - 600) (x + 400) = 0.
x2 - 200x - 240000 = 0.
Not x+200. Check this once.
There is a small mistake in your answer.
Tt will be:
(x - 600) (x + 400) = 0.
x2 - 200x - 240000 = 0.
Not x+200. Check this once.
Patel said:
5 years ago
Here we get x=1, but the question is to find time duration of a plane in bad weather, which is x+0.5 hrs. So the answer must be 1.5hrs. Right?
(1)
Nani said:
1 decade ago
Time is inversely proportional to speed so:
t1/t2=s2/s1
t2=t1+0.5 and s2=s1-200
and now solve general eqn d=t*s using above two to get t1.
t1/t2=s2/s1
t2=t1+0.5 and s2=s1-200
and now solve general eqn d=t*s using above two to get t1.
Shanthi said:
1 decade 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
Rohit said:
9 years ago
Let, x is original speed.
(600/x - 200) - (600/x) = 30/60,
Solving this equation, we get x = 600.
Duration of flight = 600/600 = 1 hr.
(600/x - 200) - (600/x) = 30/60,
Solving this equation, we get x = 600.
Duration of flight = 600/600 = 1 hr.
NEHAL ANSARI said:
9 years ago
I have one doubt, due to bad weather the time increased by 30 min then we should add 30 min in x ie (x+30/60) or not?
Please help me.
Please help me.
Lalit sharma said:
8 years ago
Another simple way of doing this is solve by;
600/(x-200)- 600/(x) = 1/2.
we get x= 600km/hr.
Time=distance/speed = 600/600 = 1hr.
600/(x-200)- 600/(x) = 1/2.
we get x= 600km/hr.
Time=distance/speed = 600/600 = 1hr.
Sahil walia said:
8 years ago
Because converting 30 min into an hour because everything is given in hour so 30 min/60 to convert into hour so here it comes 1/2.
Alokpal said:
1 decade ago
Time = distance / speed.
600 *30 /200.
30 * 3 = 90 total time.
Exact time = total time - increase time.
= 90 - 30.
= 60.
600 *30 /200.
30 * 3 = 90 total time.
Exact time = total time - increase time.
= 90 - 30.
= 60.
Legend said:
2 years ago
Time = Distance/Speed.
Therefore,
x+1/2 = 600/200
x = 3-1/2
x = 5/2.
Therefore total time = x+1/2
So, total time = 3 hr.
Therefore,
x+1/2 = 600/200
x = 3-1/2
x = 5/2.
Therefore total time = x+1/2
So, total time = 3 hr.
(49)
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