Facts: The graph refers to a plane's flight from one location to anoth

The question asks you to find out at which time interval was the flight
closer to its destination at time - X than at time - Y. This is only possible
when the distance either remains the same or increases after the time
has passed.

If you observe the graph carefully, the only time when the graph is
moving in the opposite direction(is from t=60 to t=80)

Therefore, it is the answer that you looking for. Hope that helps!

Suppose I take a flight from Mumbai to Delhi.
At the starting my Distance to destination = 1000 (suppose)
At the starting my time travelled = 0

Now as time elapses my distance from destination will reduce right? So shouldn't the answer be the maximum time elapsed? Because ultimately I will be at the destination when I actually reach Delhi and that is the moment when my time lapsed will be maximum.

I didn't understand you reasoning. Can you please explain w.r.t. my example.

Here, we are asked to find the distance w.r.t the destination in that
specific timeline. For instance if I had given you two time ranges
and asked you to compare the distances for those ranges,

Option 1 : t=10 to 20 (distance traveled 100 to 75 km) - detour due to turbulence
Option 2 : t=50 to 60 (distance traveled 275 to 375 km)

Here, the plane travels closer to the destination by 100 km in Option 2
but it travels 25 km away from the destination in Option 1. So we can
say that the plane was closer to its destination at t=10 than it was at
t=20 and Option 1 is the answer!

Hope this helps!

We have lot of points on the horizontal axis while the dropdowns have only 3-4 options, so work on the options directly to save time.

1) The plane was closer to its destination at __1__
The dropdowns tell us that the destination has to be farther even after flying for some extra time. In the graph, it will refer to points when the curve moves up as it moves right.
Look at the three options:
180-200: the curve moves down during the period, so teh destination comes closer.
60-80: the curve moves up during the period, and is our answer.
240-260: the curve, here too, moves down during the period, so the destination comes closer.

2) Of all of the 20-minute intervals beginning and ending at times labeled on the graph, the interval in which the plane traveled farthest toward its destination was the interval from __2__
We have to look at the 20-minute intervals that has the greatest downward slope: We can see that the period 160-200 has the greatest slope, so our answer should generally be within this range.
Look at the three options:
240-260: the curve moves from 20 to 5 approx during the period.
60-80: the curve moves up during the period, and we know the plane moves farther away..
180-200: the curve moves 110 to 65,so moves closest during this period and is our answer

 

 
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The graph shows distance from destination on Y axis as time progresses on X axis. It starts at 240 km and ends at 0 which makes sense. The place of origin was 240 km away from the destination and time taken for the journey was 280 mins. 

1) The plane was closer to its destination at  __________ 

The graph is falling generally which makes sense since distance from destination will decrease as time passes. But it isn't an all smooth graph. There are some inflections in the graph - what do they show? Between 60 to 80, the graph is rising. At around 60 mins, distance to destination is about 185 km and at 80 mins, distance to destination is about 197 km. So the plane had to loop around perhaps because of bad weather or something.  
Hence the plane was closer to its destination at t = 60 than at t = 80

ANSWER: at t = 60 than at t = 80


2) Of all of the 20-minute intervals beginning and ending at times labeled on the graph, the interval in which the plane traveled farthest toward its destination was the interval from ______

The 20 min intervals labeled on the graph are 0 - 20 min, 20 - 40  mins etc.  The plane travel farthest in that interval in which the plane reduced the 'distance from destination' rapidly i.e. in which the graph fell rapidly. We can see that the slope of the graph is maximum between 180 - 200 mins. 

ANSWER: 180 - 200 mins

Farthest towards its destination means going nearer to the destination or became more far to its destination?
Hence, I marked 60 to 80 - because in 60 it was nearer to its destination but in 80 it became more far.

If now I have to consider steeper slope, doesnt the slope is steep from 20 to 40 than from 180 to 200

KarishmaB maa'm , Would you like to explain a bit more on the 2nd question ? Why is the answer not t=60 to t=80 ? In that case , the flight goes upwards first and then  moves downwards.
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­'farthest toward its destination' means it reduced the distance from destination to the maximum extent. In between 60 to 80, the plane increased its distance from destination so it was moving away from the destination for the most part. In 180 - 200 mins, it covered maximum distance toward the destination ( leftover distance fell from 110 km to 70 km in the span of these 20  mins)

Hi Mam,

Destination is at 240 or 0.