To solve blood relation questions in mental ability, follow these steps:

1. Understand the Given Information:
   • Carefully read the information provided in the question.
   • Identify relationships mentioned between family members.
2. Draw a Family Tree:
   • Create a simple family tree diagram based on the given relationships.
   • Use symbols like squares for males and circles for females.
   • Connect them with lines to represent relationships.
3. Assign Symbols and Labels:
   • Assign symbols or labels to each family member (e.g., A, B, C).
   • Note the gender of each member.
4. Analyze Relationships:
   • Analyze the relationships to deduce connections between different family members.
   • Use the information to establish parent-child, sibling, or other relations.
5. Apply Logical Deductions:
   • Apply logical deductions to fill in missing information.
   • Consider possibilities and eliminate those that contradict the given information.
6. Answer the Question:
   • Once you have a clear understanding of the family tree and relationships, answer the specific question asked.
7. Practice:
   • Practice solving different types of blood relation problems to improve your speed and accuracy.

Remember, consistent practice and a systematic approach will enhance your ability to solve blood relation questions in mental ability tests.