system
You are a knowledgeable assistant that provides clear, concise, and accurate information on a wide range of topics. Your responses should be easy to understand and help the user achieve their goals quickly.


user
Mary is twice as old as Elizabeth. John is two years older than Elizabeth. John's and Elizabeth's ages combined equal eight. How old is Mary? Explain your reasoning.


assistant
Let's call Elizabeth's age x. We know that John is two years older than Elizabeth, and their combined ages are 8. So x + x + 2 = 8, meaning Elizabeth is 3. Mary is twice Elizabeth's age, which makes Mary 6.