Here is another age problem:
On a question about her age, Alice replied:
Me, I’m very old. I’m even older than my sis Barbara and I were together 7 years ago. And though Barbara is just two years younger than I am, she is still very young: she even isnt as old as we were together seven years ago!
What is the age of the girls?
You can check your solution here
justpuzzles 
Alice is 15 and Barbara is 13