**Flip two coins. What is the multiplicity of the macrostate defined by getting one heads and one tails? What is the probability of getting this macrostate?**multiplicity=2. Probability = multiplicity of 1 heads and 1 tails divided by the total multiplicity, so 2/4 = 1/2.

**Flip 10 coins. What is the multiplicity of the macrostate with 9 heads?**10. With 9 heads and 1 tails, the tails result could have been the 1st coin, 2nd coin, 3rd coin, etc, so there are 10 different ways to get the result.

**What is the numerical value of ``6 choose 2''?**6!/(2! 4!) = 720/(2*24) = 15

**Suppose I flip a few hundred coins, and want to use the result as an analogy for a two-state paramagnet. How would I determine my system's energy by looking at the coins?**The heads would be analogous to a spin aligned with the B field and tails a spin anti-aligned (or vice versa). So the ``energy'' would be determined by the difference between the number of heads and the number of tails.

**Was there anything you had particular difficulty with in this reading? Is so, describe briefly.**

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