At first glance, this puzzle looks like a simple math question. But there’s a small detail that makes it easy to get the wrong answer.
The question says:
“When I was 6 years old, my sister was half my age. Now I am 70. How old is my sister?”
Let’s solve it step by step.
Step 1: Find your sister’s age when you were 6
If you were 6 years old, your sister was half your age.
Half of 6 is:
6 ÷ 2 = 3
So, your sister was 3 years old.
Step 2: Find the age difference
You were 6, and your sister was 3.
That means the age difference between you is:
6 − 3 = 3 years
Your sister is therefore 3 years younger than you.
Step 3: Apply the same age difference today
Now you are 70 years old.
Since your sister is always 3 years younger than you:
70 − 3 = 67
So your sister is now 67 years old.
The Answer
🎯 Your sister is 67 years old.
The trick is that the phrase “half my age” only applies to the moment when you were 6. It does not mean that your sister remains half your age forever.
The age difference stays the same throughout your lives. When you were 6, she was 3—a difference of 3 years. Now that you are 70, she is 67.
Final answer: 67 years old.