
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
When one ounce of acid is added to a mixture of acid and water, the new mixture is $25\%$ acid. When another ounce of acid is added to the new mixture, the resulting mixture becomes $40\%$ acid. The percentage of acid in the original mixture is?
A) 0%
B) 10%
C) 15%
D) 20%
E) 25%

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