Problem Analysis:
The problem states:
- When you were 6 years old, your sister was half your age.
- Now you are 70 years old.
- The task is to determine how old your sister is now.
Step-by-Step Solution:
1.
Determine your sister's age when you were 6:
- You were 6 years old.
- Your sister was half your age at that time.
- Therefore, your sister's age when you were 6 is:
\[
\text{Sister's age} = \frac{6}{2} = 3 \text{ years old}
\]
2.
Calculate the age difference between you and your sister:
- When you were 6, your sister was 3.
- The age difference between you and your sister is:
\[
\text{Age difference} = 6 - 3 = 3 \text{ years}
\]
- This age difference will remain constant throughout your lives because both of you age at the same rate.
3.
Determine your sister's current age:
- Now, you are 70 years old.
- Since the age difference between you and your sister is always 3 years, your sister is:
\[
\text{Sister's current age} = 70 - 3 = 67 \text{ years old}
\]
Final Answer:
\[
\boxed{67}
\]
Parent Tip: Review the logic above to help your child master the concept of brain teasers and their answers.
