Binary Logic - Truth tellers and Liars (Logical Reasoning) for CAT 2020

This 20 minute video covers different techniques to deal with questions based on binary logic.

[gofodu]

In the first question, you need to assume that their names are Sandeep and Raj.

[anshulsancheti]

Why do people lie? 😬 Due to mere lying we are facing such questions

[nitin-pillai]

Very good content. Would love more such crisp videos from you, especially points distribution (tournaments), and missing data questions.

[vijaykalal]

How to solve this question sir?
The inhabitants of the Island of Dreams have very bright and interesting lives. Just as we earthlings
have continuity in our daily lives, the inhabitants of the Island of Dreams have continuity in both their
waking lives, as well as their dreams. As a result, the inhabitants of the Island of Dreams have great
difficulty in knowing whether they are awake or asleep at a given time. However, the inhabitants can
be classified into two broad types—Awakers and Asleepers.
An awaker is characterised by the fact that everything they believe while they are awake is true, and
everything they believe while they are asleep is false. An Asleeper on the other hand, has the
characteristic that everything he believes while asleep is true, and everything he believes while
awake is false.
11. The Island has a President, a Prime Minister and an Entertainment Minister. At one point, the
Entertainment Minister believed that his bosses were of different types. Twelve hours later,
he changed his state (from sleeping to waking or from waking to sleeping), and he then
believed that the President was an Awaker and the Prime Minister was an Asleeper. What
type is the President?
(a) Awaker
(b) Asleeper
(c) Could be either of the two types
(d) Data inconsistent
12. With reference to Question 11, what type is the Prime Minister?
(a) Awaker
(b) Asleeper
(c) Could be either of the two types
(d) Data inconsistent
13. At one time, an inhabitant believed that he was both asleep and awake, what was he really?
(a) Awaker
(b) Asleeper
(c) Could be either of the two types
(d) Data inconsistent

[ronakkabra]

The video was good and helpful. It will be great if you can come up with some more tricky set of questions after this for polishing the approach taught by you in this video

[SugamMaheshwari]

Superb quality content brother, keep it up !

[anuragkharate]

u should also explain all the cases to improve thinking level then the easy approach

[rohitsatarke]

In Lucknow village, each person belongs to one of the three categories among truth tellers (who always speak the truth), liars (who always lie) and alternators (who alternate between truth and lie in any order). B, C, D and L are Tuk Tuk residents and each of them has a different occupation among painting, carpentering, barbering, and tailoring. At least one person from each category is present among them. Each of them made exactly three statements when asked about their categories and occupations. Their statements are given below:

B: I am not a liar.
C is a painter.
Exactly two of us are liars.
C: L is a liar.
D is a barber.
I am a truth teller.
D: I am a barber.
L is a liar.
B is not an alternator.
L: C is a carpenter.
There are two alternators amongst us.
B is not a painter.
The profession of the one, who is a liar, is ?

[TrinanjanDutta]

I don't understand how Doha becomes liar
We have deduced the fact that Aaho is a liar based on Doha's statement... So Doha should be an actual truth teller... So Aaho is definitely a liar and between Bali and Charan one of them would be liar... So 2 liars and 2 truth tellers.

[hemarishu]

Tq very much sir now i'm clear with this concept

[ashishsingla]

Thank you so much Sir. Kaafi Badiya tarike se samjhaya aapne.

[marygraceomingo]

Hi po pakalabit nmn po sa bahay ko salamat wait ko po