Tips and Tricks for Blood Relations | Logical Reasoning (LR) and Data Interpretation (DI) - CAT PDF Download

Candidates can discover various tips and strategies below to efficiently solve questions in the Blood Relation reasoning section.

• Tip 1: When tackling questions in the Blood Relation reasoning section, candidates should treat "ME" as the introducing person to quickly answer posed questions.
• Tip 2: In the Coded Relation type blood relation section, candidates should carefully examine all options, including gender considerations. By eliminating incorrect options, candidates can arrive at the final conclusion.
• Tip 3: Avoid making predictions about a person's gender based on their name unless explicitly mentioned, as this may lead to an inaccurate answer.
• Tip 4: It's crucial to recognize that being the "only son" or "only daughter" does not necessarily imply being the only child. If a blood relation question states that A is the only son of B, A could potentially have both a son and a daughter or just one son.
• Tip 5: Identify the two individuals between whom the relationship needs to be determined. Then, using the relationships between other family members provided as intermediaries, attempt to establish the connection between the two required persons.
• Tip 6: Relating the given relations in questions to personal relationships will enhance understanding and aid in answering questions more effectively.
• Tip 7: Utilizing pictorial representation is advisable for solving questions. This form allows candidates to systematically arrange data, making it easier to comprehend the relationships presented in the questions.
• Tip 8: In pictorial representation, use '+' for denoting a male gender and use ' - ' for denoting a female gender.

Solved Example

Example 1: Introducing a lady at the party, Goldy told her friend, “She is sister-in-law of my only brother who is father of Ganesh who is grandson of Navya’s husband who is my father who has only two child.” How is Ganesh related to that lady? 

Sol: If we analyze all the statements given above in the question and draw the family tree for the same By this, we can easily see that Ganesh is nephew of the Lady.

Example 2: Given Directions
M@N means M is the wife of N
M#N means M is the son of N
M5N means M is the sister of N
M$N means M is the father of N

Which of the following expressions shows I as the brother of H?
(a) H#P$I, 
(b) H%P$I, 
(c) I%H$P, 
(d) H%I$P

Sol: Option D is correct.
Explanation:

The above statements implies the following things.
M is

From the above options, we need to find an expression which represents I as the brother of H.
So, check all the options and eliminate those in which either the gender is of I is unknown, or I is female.
In the above question, @ and % represents wife and sister respectively such as female so eliminate all such options. And if in any expression, I is present in the end then it means that the gender of I will be unknown so eliminate such options too.
From the above trick we can eliminate options 1,2, and 3. Hence in the expression “H%I$P”, I is the brother of H.

Example 3: Read the following instructions:

1. A + B indicates A is the brother of B;
2. A – B indicates A is the sister of B and
3. A x B indicates A is the father of B

Which of the following means that C is the son of M?

1. M – N x C + F
2. F – C + N x M
3. N + M – F x C
4. M x N – C + F

Sol:  In these types of questions, we have to analyze each option
In Option A, 
According to this option NxC indicates N is the father of c. Hence it is wrong. 
In Option B,
 According to this option C is the brother of N who is the father of M. Hence it is wrong. 
In Option C ,
According to this option Fx C indicates F is the father of C. Hence it is wrong. 
In Option D,
According to this option M is the father of N who is the sister of C hence C and N are siblings and C is the brother of F so, C is male, Hence C is the son of M.

Hence, Option D is the correct answer.

Example 4: Read the following information carefully and answer the questions which follow:
Mr. Rajat Chopra and his wife Nikita Chopra have 3 sons whose names are Ramesh, Suresh and Umesh. Mishra family is a neighbor of the Chopra's.
Mr. Amit Mishra and his wife Neha Mishra have 2 daughters whose names are Payal and Ruchi. The two neighboring families go to Kerala for a vacation. They decide to go for boating but no boat could carry more than 3 members. So they hire 3 boats. None of the children know how to row a boat, so at least one of the adults have to be there on each boat. Moreover, no boat has all the three members from the same family.

Q-1:  If Neha and Ruchi are on the same boat, which of the following could be a list of people on another boat?
a) Ramesh, Amit, Payal
b) Ramesh, Suresh, Amit
c) Ramesh, Payal, Suresh
d) Amit, Payal, Nikita

Sol: Option 'B' is correct.
We know that none of the boats have all the members from the same family. So each boat must have at least 1 member from each of the two families. 
Neha and Ruchi are on the same boat. So only two people from Mishra family are remaining. 
Both of them need to be on different boats. 
Hence options A and D can be ruled out because they have Payal and Amit on the same boat. 
Option C is also not possible since it does not have any adult on the boat

Q 2: If Rajat and Amit are in the same boat and each of the three brothers are on different boats, then which of the following is necessarily true?
a) Every boat has both males and females on it.
b) One of the boats has only females on it.
c) One of the boats has only males on it.
d) The two sisters are on the same boat.

Sol:  Option C is Correct.
If Rajat and Amit are on the same boat then the other two boats would be rowed by Neha and Nikita. 
It is known that each of the brothers are on different boats. So one of them will be on Rajat and Amit's boat. 
Hence there will be one boat with only males. 

Q 3: If the three children from the Chopra family ride in different boats then which of the following is definitely false?
I. Rajat and Nikita are rowing in the same boat.
II Amit and Neha are rowing in the same boat.
a. I only
b. II only
c. Both I and II
d. Neither I nor II

Sol: Option 'A' is correct.
The three boys are rowing in different boats. We know that there are only three boats and each boat can carry three persons. 
Hence Amit and Nikita cannot be on the same boat as that would mean that one of the boats has all the members from the Chopra family. 
So I is definitely false.
Statement II can be true as well false. It can be true if the two people travel in one boat while Amit and Nikita row the other two boats. Hence nothing can be said with certainty about statement II. 

Q-4: If Nikita and Amit are on the same boat then which of the following cannot be the combination of people on any boat?
a) Ramesh, Neha, Ruchi
b) Neha, Ramesh, Suresh
c) Neha, Ruchi, Umesh
d) Neha, Suresh, Rajat

Sol:  Option 'D' is the answer.
Neha, Suresh and Rajat cannot be on the same boat. This is because we know that one of the adults have to be there on each boat. Since Nikita and Amit are already on the same boat, Neha and Rajat have to on the other two boats. If they are on the same boat then there will be no adult on the third boat. Hence, option D is the combination that is not possible.