Battery recall

A company has discovered that a recent batch of batteries had manufacturing flaws, and has issued a recall. You have 10 batteries covered by the recall, and 3 are dead. You choose 2 batteries at random from your package of 10.

a) Has the assumption of independence been met? Explain.

b) Create a probability model for the number of good bat- teries chosen.

c) What's the expected number of good batteries?

d) What's the standard deviation?