Solving Blood Relation Puzzles: Decoding Relationships

This question asks us to determine which of the given coded expressions represents the relationship where O is the sister of L. We are provided with specific codes for different relationships:

• G \({+}\) H means G is daughter of H.
• G \({-}\) H means G is father-in-law of H.
• G \({*}\) H means G is husband of H.

We need to analyze each option based on these rules to find the one that results in O being the sister of L. Remember that G is the first person mentioned and H is the second person in each coded relation (e.g., G \({+}\) H).

Analyzing the Options for Blood Relations

Let's examine each option step-by-step:

Option 1: O \({*}\) N \({-}\) M \({+}\) L

• O \({*}\) N: O is husband of N. This means O is male and N is female.
• N \({-}\) M: N is father-in-law of M. This means N is male and the father of M's spouse.

From the first relation (O \({*}\) N), we know N is female. From the second relation (N \({-}\) M), we know N is male. This creates a gender contradiction for N based on the given rules. Therefore, this option is invalid.

Option 2: O \({-}\) N \({*}\) M \({+}\) L

• O \({-}\) N: O is father-in-law of N. This means O is male and the father of N's spouse.
• N \({*}\) M: N is husband of M. This means N is male and M is female.
• M \({+}\) L: M is daughter of L. This means M is female and L is a parent of M.

Let's combine these:

• From O \({-}\) N, O is father of N's spouse.
• From N \({*}\) M, N is husband of M, so M is N's spouse.
• Combining these, O is father of M. So O is male.
• From M \({+}\) L, M is daughter of L. M is female.

So, M is the daughter of L, and O is the father of M. This means M's parents are O and L. Since O is the father, L must be the mother. Therefore, O is the husband of L, and L is the wife of O. This does not show O is the sister of L.

Option 3: O \({+}\) M \({-}\) N \({*}\) L

• O \({+}\) M: O is daughter of M. This means O is female and M is a parent of O.
• M \({-}\) N: M is father-in-law of N. This means M is male and the father of N's spouse.
• N \({*}\) L: N is husband of L. This means N is male and L is female.

Let's combine these relations:

• From N \({*}\) L, N is husband of L, so L is N's spouse.
• From M \({-}\) N, M is father-in-law of N, meaning M is the father of N's spouse. Since L is N's spouse, M is the father of L. This also confirms M is male, consistent with M being father-in-law.
• From O \({+}\) M, O is daughter of M.

So, we have M is the father of O, and M is the father of L. Both O and L are children of M. We know O is female (O \({+}\) M). We know L is female (N \({*}\) L). Since O and L are both children of the same parent (M) and both are female, O is the sister of L. This option correctly shows that O is the sister of L.

Option 4: O \({-}\) N \({+}\) M \({*}\) L

• O \({-}\) N: O is father-in-law of N. This means O is male and father of N's spouse.
• N \({+}\) M: N is daughter of M. This means N is female and M is a parent of N.
• M \({*}\) L: M is husband of L. This means M is male and L is female.

Let's combine these relations:

• From M \({*}\) L, M is husband of L. M is male, L is female.
• From N \({+}\) M, N is daughter of M. N is female. Since M is male, M is the father of N. So L is the mother of N.
• From O \({-}\) N, O is father-in-law of N. O is male. O is father of N's spouse.

In this option, O is the father of N's spouse. N is the daughter of M and L. The expression does not define N's spouse. While we know the relationships between N, M, and L (N is daughter of M and L, M is husband of L), O's relationship is defined with N's *spouse*, who is not explicitly mentioned as M or L or related to them in a spousal way to N. This option does not establish O as L's sister.

Conclusion

Based on the step-by-step analysis, only Option 3, O \({+}\) M \({-}\) N \({*}\) L, correctly establishes the relationship where O is the sister of L according to the given coding rules.

Revision Table: Key Blood Relation Terms

Additional Information: Strategies for Blood Relation Problems

Solving blood relation problems with codes requires careful attention to detail and systematic analysis. Here are some tips:

• Write down the meaning of each code clearly, noting the gender of the person before and after the symbol if implied.
• Break down the expression into smaller parts (two variables connected by one symbol).
• Trace the relationships sequentially from left to right or right to left, building a family tree or list of connections.
• Pay close attention to gender indicated by the relations (e.g., "daughter" implies female, "husband" implies male). Check for gender consistency throughout the chain.
• When tracing relations, work outwards from a known relationship. For example, if you know 'A is father of B' and 'B is spouse of C', you can deduce 'A is father-in-law of C'.
• For complex expressions, drawing a simple diagram or family tree can be helpful to visualize the connections and genders.