
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
Given the original cost per item was 100 yuan, and after two consecutive cost reductions the current cost is 81 yuan, find the average percentage decrease per reduction.

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