
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
Suppose that 9 boys and 15 girls line up in a row, but the arrangement must start with a boy and end with a girl. Let $T$ be the number of places in the row where a boy and a girl are standing next to each other. Calculate the average value of $T$ when all possible orders of these 24 people under the given conditions are considered.

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