So the age difference is:
10 − 5 = 5 years
That difference stays constant forever.
Step 3: Calculate her current age
Now you are 54, so:
Sister’s age = 54 − 5 = 49
Final Answer:
👉 She is 49 years old.
Why people get confused
Most people try to solve it algebraically without realizing the puzzle hides a specific starting point. Once you see that the age gap never changes, the answer becomes very simple.
