
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
Two construction teams, A and B, start excavating a tunnel from both ends simultaneously. Team A excavates 'a' meters per day, and team B excavates 'b' meters per day. After 120 days, they finish the excavation.
(1) How long is this tunnel?
(2) When a=11 meters and b=9 meters, how long is this tunnel?

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