SSC CGL Reasoning · Blood Relations

Family Puzzles

A set of clues about a whole family, often out of order, from which you build one tree and then answer a relation or count the men, women or couples.

All Blood Relations notes

Why this matters

Eleven questions in the bank, spread over all three years, eight of them EASY. They take longer than a statement chain only because the clues do not come in order, so the time goes into choosing which clue to draw first.

Concept 1 of 2: Placing clues that come out of order

In a family puzzle you cannot draw the clues one by one as you read, because a clue may name two people who are not on the tree yet. Draw first the clue that fixes the most, then hang the others on it.

Definition

1. Read every clue once before drawing anything. 2. Draw first the clues that fix a pair for certain: a married couple, an 'only daughter', an 'only son-in-law'. 3. Park a clue whose people are not on the tree yet; come back to it when one of them is. 4. Mark each gender the moment a word fixes it. A square for male and a circle for female is quick. 5. Answer once every clue the question needs is placed. A clue about a person the question never asks about may be there only to complete the family.

Worked example

J is the father of K. L is the only daughter of M, a woman. K is the husband of L. N is the son of K. How is M related to N?

Practice this conceptself-check · 3 quick reps

The same idea in a real exam question:

SSC CGL · 2024 · Tier I, 17 Sep 2024, Shift 1 · Q11Moderate

Example 1 · Blood Relations · Family Puzzles

G is the brother of F. E is the father of K.. C is the daughter of A. F is the mother of E. C is the sister of E. How is G related to A?

Forcing a clue before its people are placed

If neither person in a clue is on the tree yet, drawing it anyway means guessing where it joins. Park it, place the clues that fix pairs, and it will usually join in one obvious place.

Letting a spare clue change the answer

Family puzzles often add clues about people the question does not ask about. Draw them if they help, but do not change a relation you have already fixed to make a spare clue feel used.

Drill 6 more on placing clues that come out of order

Concept 2 of 2: Families of a given size: couples, generations and counting members

Some puzzles give the size of the family and the number of generations or couples, then ask who is the mother or how many men there are. The size is a check you can use: every named person must end up on the tree exactly once.

Definition

1. List the named people down the side of your page. Beside each, write the gender and the level as soon as a clue fixes them. 2. A married couple stands on one level; 'three generations' means three levels, grandparents at the top. 3. A gender often comes from a clue that is not about gender: a person who has a wife is male, a person who has a husband is female. 4. Count only when every person in the count has a fixed gender. If one is still open, find the clue that fixes them first. 5. Check that the number of people on the tree equals the family size.

Worked example

A family has five members: P, Q, R, S and T. P and Q are a married couple, and Q is a woman. R and S are their children, and S is a daughter. T is the wife of R. How many males are in the family?

Practice this conceptself-check · 3 quick reps

The same idea in a real exam question:

SSC CGL · 2025 · Tier I, 21 Sep 2025, Shift 1 · Q17Moderate

Example 2 · Blood Relations · Family Puzzles

Directions: These questions are based on the following information. There are 7 family members: P, Q, R, S, T, U and V going to a party. There are three generations in which only two are married couples. P is the grandfather of U who is a male. R is the son in law of S.V is the son of Q.S has only two children, both of the same gender. T is the sister in law of R. How many males are there?

Counting a person twice

The same person often appears in two clues, once as someone's son and again as someone's husband. Count the names on your list, not the times a name is mentioned.

Counting an open gender as male

A person whose gender no clue fixes cannot be counted as a man or a woman. When the question asks for a count, find the clue that settles that person before you add up.

Drill 3 more on families of a given size: couples, generations and counting members

Summary — formulas & gotchas at a glance

A revision cheat-sheet for the formulas and gotchas above. Click any concept name to jump back to its full explanation.

Watch out for (4)

Forcing a clue before its people are placed
→ Placing clues that come out of order
Letting a spare clue change the answer
→ Placing clues that come out of order
Counting a person twice
→ Families of a given size: couples, generations and counting members
Counting an open gender as male
→ Families of a given size: couples, generations and counting members

Test yourself on Blood Relations

20 past SSC CGL questions from this chapter, timed at 12 minutes and marked the way the exam marks it. You see your score and every answer the moment you finish. Free to start.

Take the Blood Relations chapter test Drill all 11 questions