
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 water supply company charges for water usage as follows: if the monthly usage does not exceed 10 cubic meters, the charge is 1.5 yuan per cubic meter; if the monthly usage exceeds 10 cubic meters, the excess part is charged at 2 yuan per cubic meter.  
(1) If resident A used 8 cubic meters of water in December last year, the water fee to be paid is:  
(2) If resident B paid 22.8 yuan for water in December last year, the water usage of resident B in December last year was:  
(3) If resident C paid m yuan for water in December last year, what was the water usage of resident C in December last year? (Express in terms of m)

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