
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
Classes A and B participated in the same subject exam, with 50 students in Class A and 40 students in Class B. The average score of Class A is 76 with a variance of 96, while the average score of Class B is 85 with a variance of 60. What is the variance of the scores of all 90 students from Classes A and B combined?

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