
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
A certain store purchased a batch of daily necessities at a unit price of $20. If they are sold at a unit price of $30, then 400 items can be sold in one month. According to sales experience, increasing the selling price will lead to a decrease in sales volume, that is, for every $1 increase in the selling price, the sales volume decreases by 20 items. What selling price will yield the maximum profit in one month?

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