Coded Relations (+ − × ÷)
Coded Relations (+ − × ÷)
Coded Relations (+ − × ÷)
- Blood Relations
- Coded Relations (+ − × ÷)
Read relations written with symbols and work out how the two end-people are related.
🎯 Learning Objective
Read relations written with symbols and work out how the two end-people are related.
💡 Concept
- Symbols stand for relationships, given by a legend you must read carefully
- This chapter's legend: 'P + Q' = P is the father of Q
- 'P − Q' = P is the mother of Q
- 'P × Q' = P is the brother of Q
- 'P ÷ Q' = P is the sister of Q
- Read strictly left to right and build a mini family chain
🧮 Key Formulas
+ = father of
>
− = mother of
>
× = brother of
>
÷ = sister of
>
Read the expression strictly left → right
✏️ Easy Example
Q. Using + = father of, − = mother of, × = brother of, ÷ = sister of: in 'M + N ÷ O', how is M related to O?
- M + N: M is the father of N
- N ÷ O: N is the sister of O, so N and O are siblings
- M, being father of N, is also the father of O
Answer: Father
🇮🇳 Real-Life Example
Filling a bank or exam form's relationship column with codes ('F' for father, 'M' for mother) is the same shorthand — symbols instead of full relation names.
📝 Exam-Level Example
Q. With + = father of, − = mother of, × = brother of, ÷ = sister of: in 'P × Q − R', how is P related to R?
- P × Q: P is the brother of Q
- Q − R: Q is the mother of R
- P is the brother of R's mother → P is R's maternal uncle
Answer: Maternal uncle
📝 Exam-Level Example
Q. Using the same legend, which expression shows that 'A is the maternal grandmother of D'? (i) A − B − D (ii) A + B − D
- Option (i): A − B means A is mother of B; B − D means B is mother of D
- So A is the mother of D's mother = D's maternal grandmother
- Option (ii) makes A the father's side and male, so it fails
Answer: A − B − D
📝 Exam-Level Example
Q. With the same legend, in 'P ÷ Q × R', how is P related to R?
- P ÷ Q: P is the sister of Q
- Q × R: Q is the brother of R, so Q and R are siblings
- P, being sister of Q, is also the sister of R
Answer: Sister
🪄 Memory Trick
Convert each symbol to a plain sentence as you go: 'father of', 'mother of', … then read the sentences together to get the final link.
⚠️ Common Mistakes
- ❌ Using a legend from memory instead of the one printed in the question
- ❌ Losing gender — × is specifically brother (male), ÷ is sister (female)
- ❌ Reading right to left instead of left to right
🏆 Exam Tips
- ✅ Rewrite the whole expression in words on your rough sheet before deciding
- ✅ Watch the last symbol's gender — it often fixes uncle vs aunt, grandfather vs grandmother
📌 Summary
- Read the given legend first — never assume symbols
- Translate each symbol into 'X is the ___ of Y'
- Chain the mini-relations left to right
- Keep gender attached to × (brother) and ÷ (sister)