Question

If 'P+Q' means P is brother of Q, 'PQ' means P is sister of Q, 'P-Q' means P is mother of Q and 'P@Q' means P is father of Q, then which of the following is correct about E+F@GH?

• A. G is mother of H
• B. G is daughter of F
• C. F is brother of E
• D. E is sister of H
• E. F is sister of E

Hint:

Always identify the gender of the persons mentioned. For example, in $P@Q$, we know $P$ is male (father), but we don't know $Q$'s gender until the next symbol ($GH$ tells us $G$ is female). This "Gender Check" can often eliminate 2-3 wrong options instantly!

Answer 1

The Correct Option is B

Concept:
In coded blood relation problems, we decode the expression symbol by symbol to build a family tree. It is helpful to denote gender ($+$ for male, $-$ for female) and generations (vertical lines for parent-child, horizontal lines for siblings).

Step 1: Decode the relationship symbols.
• + $\to$ Brother (Male)
• $\to$ Sister (Female)
• - $\to$ Mother (Female)
• @ $\to$ Father (Male)

Step 2: Analyze the expression E+F@GH.
• E+F: E is the brother of F. (E is Male, E and F are in the same generation).
• F@G: F is the father of G. (F is Male, G is in the next generation below F).
• GH: G is the sister of H. (G is Female, G and H are siblings).

Step 3: Verify the options based on the decoded tree.
• Option A: G is mother of H? Incorrect. G is the sister of H.
• Option B: G is daughter of F? Correct. Since F is the father of G and G is female (sister of H), G is F's daughter.
• Option C: F is brother of E? Correct in relationship, but in 'E+F', E is the brother of F. While they are brothers, Option B is a more specific derivation of the G-F relationship. However, based on 'E+F', E is male; the gender of F is determined by 'F@G' (Father), making F male as well.
• Option D/E: Incorrect. E is male (brother), and F is male (father).