The demand for Amazon$$s Kindle e$-$readers can be approximated by

$()=230\mathrm{.}01$

q

$($

p

$)$

$=$

$23$

e

$$

$0\mathrm{.}01$

p

million units per year for $20<=<=250$

$20$

$<=$

p

$<=$

$250$

where $$

p

is the price charged by Amazon. Use this demand equation to answer the following questions.