
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 school has 120 students and 6 teachers. In the first period, each student is taking one class, and each teacher is teaching one class. The enrollments in the classes are 60, 30, 20, 5, 3, 2. Compute $t - s$, where $t$ is the average number of students that a randomly chosen teacher teaches, and $s$ is the average number of students including a randomly chosen student in their class.
A) -35
B) -21
C) 0 
D) 21
E) 35

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