Fix typos

Advanced/Stopping Problems/parts/0 probability.tex

@@ -46,17 +46,17 @@ a \textit{random variable} is a function from $\Omega$ to a specified output set
 
 For example, given the three-coin-toss sample space
 $\Omega = \{
-	\texttt{TTT},~ \texttt{TTH},~ \texttt{THT},~
-	\texttt{THH},~ \texttt{HTT},~ \texttt{HTH},~
-	\texttt{HHT},~ \texttt{HHH}
+	\texttt{TTT},~ \texttt{TTH},~ \texttt{THT},~ % spell:disable-line
+	\texttt{THH},~ \texttt{HTT},~ \texttt{HTH},~ % spell:disable-line
+	\texttt{HHT},~ \texttt{HHH} % spell:disable-line
 \}$,
 We can define a random variable $\mathcal{H}$ as \say{the number of heads in a throw of three coins}. \par
 As a function, $\mathcal{H}$ maps values in $\Omega$ to values in $\mathbb{Z}^+_0$ and is defined as:
 \begin{itemize}
-	\item $\mathcal{H}(\texttt{TTT}) = 0$
-	\item $\mathcal{H}(\texttt{TTH}) = 1$
-	\item $\mathcal{H}(\texttt{THT}) = 1$
-	\item $\mathcal{H}(\texttt{THH}) = 2$
+	\item $\mathcal{H}(\texttt{TTT}) = 0$ % spell:disable-line
+	\item $\mathcal{H}(\texttt{TTH}) = 1$ % spell:disable-line
+	\item $\mathcal{H}(\texttt{THT}) = 1$ % spell:disable-line
+	\item $\mathcal{H}(\texttt{THH}) = 2$ % spell:disable-line
 	\item ...and so on.
 \end{itemize}
 
@@ -70,7 +70,7 @@ the set of outcomes that produce that value. \par
 \vspace{2mm}
 
 For example, if we wanted to compute $\mathcal{P}(\mathcal{H} = 2)$, we would find
-$\mathcal{P}\bigl(\{\texttt{THH}, \texttt{HTH}, \texttt{HHT}\}\bigr)$.
+$\mathcal{P}\bigl(\{\texttt{THH}, \texttt{HTH}, \texttt{HHT}\}\bigr)$. % spell:disable-line
 
 
 \problem{}

Advanced/Stopping Problems/parts/2 secretary.tex

@@ -191,7 +191,7 @@ what is the probability that we select the best candidate? \par
 Call this probability $\phi_n(k)$.
 
 \begin{solution}
-	Using \ref{seca} and \ref{secb}, this is straightfoward:
+	Using \ref{seca} and \ref{secb}, this is straightforward:
 	\[
 		\phi_n(k)
 		= \sum_{x = k}^{n}\left( \frac{1}{n} \times \frac{k-1}{x-1} \right)