
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 box contains six cards numbered from 1 to 6. Four cards are selected randomly without replacement from the box. Calculate the probability that the sum of the numbers on the selected cards is exactly 15.

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