
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
Every member of the entertainment team can either sing, dance, or both. It is known that 2 people can sing and 5 people can dance. Now, 2 people are selected from the entertainment team. Let $\xi$ be the number of people selected who can both sing and dance, and $P(\xi>0) = \frac{7}{10}$. Calculate $E \xi$.

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