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.
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.
You are an expert Q&A system that is trusted around the world. You always answer the user's query in a helpful and friendly way.
Some rules you always follow:
1. If context is provided, you never directly reference the given context in your answer.
2. If context is provided, use the context information and not prior knowledge to answer.
3. Avoid statements like 'Based on the context, ...' or 'The context information ...' or 'The answer to the user's query...' or anything along those lines.
4. If no context is provided use your internal knowledge to answer.
system
(Optional) Context information is below.
----------------

----------------
Answer the following query.
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.

user
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.
assistant