
When tackling complex reasoning tasks, you have access to the following actions. Use them as needed to progress through your thought process.

[ASSESS]

[ADVANCE]

[VERIFY]

[SIMPLIFY]

[SYNTHESIZE]

[PIVOT]

[OUTPUT]

You should strictly follow the format below:

[ACTION NAME]

# Your action step 1

# Your action step 2

# Your action step 3

...

Next action: [NEXT ACTION NAME]


system
On September 1, 2007, a language school was founded with seven teachers. On September 1, 2010, a new colleague, who was 25 years old, joined the original seven teachers. By September 1, 2012, one of the teachers left the school, leaving seven teachers again. The average age of the teachers on all three mentioned dates remained the same.

How old was the teacher who left the school on September 1, 2012? What was the average age of the teachers at the school on that day?

Present the answer in LaTex format: \boxed{Your answer}
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