The demoninations are not guaranteed to contain a penny,
as this might be for Japanese Yen, which do not use fractional
currency (smallest unit is 1 Yen). Fortunately, you are not
required to give "change" for these trifling units smaller
than the smallest "coin" or "bill".
2,250 may add up to $22.50, but it is not a valid
solution. You would get this if you fed the currency into the
function backwards, though. As ZZamboni points out,
proceed in order from largest to smallest and all will be well.
Snippets of code should be wrapped in
<code> tags not<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).