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 19 of 21.
Madhava said:
8 years ago
How 600/x-600/x+1/2=200?
Why we take the difference and why it equal to 200?
Why we take the difference and why it equal to 200?
Madhav said:
8 years ago
Can anyone explain 1st step, I'm not understanding.
Madhav said:
8 years ago
How 600/x-600/x+2=200?
Please explain this step.
Please explain this step.
Yash said:
8 years ago
Hey guys!
Actually x=3/2 is the correct answer.
if new time = 1.5 hrs(i.e 3/2 hrs)
then original time=1.5-0.5(i.e 30 minutes)
=1 hr.
Then original speed = 600 kmph (since 600 km in an hr)
new speed = 600-200
= 400 kmph.
New time = 600/400
= 1.5 hrs (fits correctly with x=1.5 i.e our initial assumption).
Now,
x=1
original time =30 minutes= 0.5 hr
original speed = 600 kmph * 05 hr
= 1200 kmph
new speed = 1200-200
= 1000 kmph.
new time = 600/1000
= 36 minutes.
Since x=30 minutes; x is not equal new time.
so conclusion:- time =1.5 hrs (answer choices are incorrect).
Actually x=3/2 is the correct answer.
if new time = 1.5 hrs(i.e 3/2 hrs)
then original time=1.5-0.5(i.e 30 minutes)
=1 hr.
Then original speed = 600 kmph (since 600 km in an hr)
new speed = 600-200
= 400 kmph.
New time = 600/400
= 1.5 hrs (fits correctly with x=1.5 i.e our initial assumption).
Now,
x=1
original time =30 minutes= 0.5 hr
original speed = 600 kmph * 05 hr
= 1200 kmph
new speed = 1200-200
= 1000 kmph.
new time = 600/1000
= 36 minutes.
Since x=30 minutes; x is not equal new time.
so conclusion:- time =1.5 hrs (answer choices are incorrect).
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.
S. M said:
7 years ago
@All.
The Original duration or the duration it has taken? Confused by the answer.
I think original duration is 1 hour but it has taken 30 mins more due to bad weather. Am I right?
Please anyone explain me.
The Original duration or the duration it has taken? Confused by the answer.
I think original duration is 1 hour but it has taken 30 mins more due to bad weather. Am I right?
Please anyone explain me.
Manju said:
7 years ago
Thank you @Kiran.
Prachi said:
7 years ago
Thank you @Saravanakgopi.
Nikhil said:
7 years ago
Thanks @Kiran.
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?
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers