Blood Relation Basics: Family Tree and Symbols

Blood relation is one of the most predictable scoring blocks in SBI Clerk Reasoning, usually worth two to three near-guaranteed marks. Every question reduces to placing people on a family tree and reading the link. The candidates who lose marks here do not lack knowledge of relations; they try to hold the whole chain in their head instead of drawing it. A tiny diagram turns a confusing sentence into a two-second answer, so the first habit to build is: never solve a blood-relation question without a quick sketch.

The Symbol System

Use a fixed set of symbols so your diagram is always readable. Draw a horizontal line for a married couple or a same-generation pair, and a vertical or slanting line downward for a parent-to-child link. Mark males with a plus sign and females with a minus sign, or simply circle females, so gender never gets lost. Keeping the notation identical in every question means your eye reads the finished tree instantly instead of decoding fresh symbols under time pressure.

Generation Levels

Arrange the tree in horizontal layers, one per generation, and this is the single most powerful habit in the topic. Grandparents sit on top, parents in the middle, children below, so anyone on the same line is a sibling, spouse or cousin, and a jump between lines is always a parent-child step. Once people are placed on the correct level, the required relation almost reads itself off the diagram without any further thinking, because the layout itself encodes who is older and who is younger.

Maternal and Paternal Sides

SBI Clerk loves the maternal-versus-paternal twist, so fix the vocabulary early. Anyone reached through your mother is maternal — maternal uncle is mother's brother, maternal grandfather is mother's father. Anyone reached through your father is paternal — paternal aunt is father's sister. When a question names a side, trace the path through that parent only and you will never confuse a mother's brother with a father's brother.

Solved Example

Example: 'Pointing to a man, Rita said, He is the son of my grandfather's only son.' Her grandfather's only son is Rita's father, so the man is her father's son — that is Rita's brother. Drawn as three levels, the answer is immediate.

✗ Reading 'grandfather's only son' as the grandfather himself  |  ✓ Tracing it as Rita's father, so his son is Rita's brother

Reading the Sentence in the Right Direction

Blood-relation sentences are deliberately worded to be read backwards, and reading them the wrong way is the commonest error in the whole topic. Start from the far end of the phrase and unwind it toward the speaker: in 'the brother of the daughter of my father', begin with 'my father', step down to 'his daughter', then across to 'her brother', which lands on the speaker's own brother. Underline each named person as you go and place them on the tree in order, so the sentence becomes a short walk from one node to the next rather than a knot to untangle. This unwinding discipline, combined with a level-by-level diagram, is what lets a strong candidate finish a basic blood-relation question in under fifteen seconds while a weaker one rereads the sentence three times and still guesses.