
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
(The full score for this question is 15 points) When the purchase price of a product is 80 yuan and it is sold for 90 yuan each, 400 units can be sold. It is known that for every 1 yuan increase in price, the sales volume decreases by 10 units. To achieve the maximum profit, what should be the selling price per unit?

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