<<echo=FALSE, results=hide>>=
SYM <- c(EUR = "€", USD = "\\\\$", GBP = "£")
CURR <- c(EUR = 1, USD = 1.3109, GBP = 0.8431)
ADIDAS <- 84.8492
nr <- sample(10:100, 1)
cu <- sample(names(CURR), 1)
x <- nr * ADIDAS * CURR[cu]
@

\begin{question}
On 2013-05-03 one Euro (\Sexpr{SYM["EUR"]}) was buying
\Sexpr{CURR["USD"]} US Dollars (\Sexpr{SYM["USD"]}) and
\Sexpr{CURR["GBP"]} British Pounds (\Sexpr{SYM["GBP"]}).
At Frankfurter Börse around noon adidas AG was the largest winner
compared with the day before with a price of
\Sexpr{SYM["EUR"]} \Sexpr{ADIDAS} per share.
If you buy \Sexpr{nr} shares, how much are they worth in
\Sexpr{SYM[cu]}?
\end{question}

\begin{solution}
The worth in \Sexpr{SYM[cu]} is the
number of shares $\times$ stock price $\times$ exchange rate, i.e.,
$\Sexpr{nr} \times \Sexpr{ADIDAS} \times \Sexpr{CURR[cu]} \approx \Sexpr{x}$.
\end{solution}

%% \extype{num}
%% \exsolution{\Sexpr{fmt(x, digits = 3)}}
%% \exname{Currency exchange rates}
%% \extol{0.01}