CAT Questions | CAT LR DI

CAT DI LR section has become increasingly tough beginning from 2015. However, Understanding the basics of Bar graphs, Pie Charts, Multiple graphs, Line Graphs etc forms an integral part of solving tougher CAT level DI LR questions for the CAT Exam. This question is from CAT 2017 Slot 1 CAT DILR.

CAT DILR : 2017 slot 1 questions

Cars Travel Route

A new airlines company is planning to start operations in a country. The company has identified ten different cities which they plan to connect through their network to start with. The flight duration between any pair of cities will be less than one hour. To start operations, the company has to decide on a daily schedule.

The underlying principle that they are working on is the following:

Any person staying in any of these 10 cities should be able to make a trip to any other city in the morning and should be able to return by the evening of the same day.

Question 4: Suppose the 10 cities are divided into 4 distinct groups G1, G2, G3, G4 having 3, 3, 2 and 2 cities respectively and that G1 consists of cities named A, B and C. Further, suppose that direct flights are allowed only between two cities satisfying one of the following:
1. Both cities are in G1
2. Between A and any city in G2
3. Between B and any city in G3
4. Between C and any city in G4

However, due to operational difficulties at A, it was later decided that the only flights that would operate at A would be those to and from B. Cities in G2 would have to be assigned to G3 or to G4.
What would be the maximum reduction in the number of direct flights as compared to the situation before the operational difficulties arose? (TITA)

Video Explanation

Explanatory Answer

Method of solving this Question on CAT DILR

General Solution

It is to be noted that as per new conditions, the flights between A and C is not possible, as well as flights between A and any city in G2 is not allowed.
The cities in G2 are shifted to group G3 and G4.
The new group og cities would look like this:


Consider the group of cities in G3, only flights from/to B are possible.
Total flights for G3 = 4 * 4 = 16 flights.
Similarly, for group G4,
Total flights for G4 = 4 * 3 = 12 flights.
Only flights in G1 and the flights from A are to be accounted.
The flights in G1 is only between B and C,
Total flights = 4
Since, flights between A and C are not possible, we have to consider only flights between A and B, which is 4.
Total flights operated = 16 + 12 + 4 + 4 = 36.
Maximum reduction in the number of flights = 40 - 36 = 4 flights.

The question is " What would be the maximum reduction in the number of direct flights"

Hence, the answer is "4".

4 flights is the correct answer.