Linking two enumerate lists: One to one linked

Question

Suppose I have an enumerate list of problems (say 50 questions) in a page and another enumerate list of hints in another page (50 items). How can one link each item of the problem-list to the corresponding item of the hint-list and vice-versa? I want to click to the problem item to go to the corresponding hint item and vice-versa. Example: a click on problem item 34 brings me to the hint item 34; and also a click on the hint item 34 brings me to the problem item 34.

The following example is only one sided, i.e., one can go from question to the answer but not from answer to the question. If there is a way, please help.

\documentclass{article}
\usepackage{hyperref}
\pagestyle{empty}
\begin{document}
Questions
\begin{enumerate}
\item[\ref{item:earth}.] What is the diameter of Earth?
\item[\ref{item:dwarfs}.] How many dwarfs were there in
  \emph{Sleeping Beauty?}
\end{enumerate}

\newpage
Answers
\begin{enumerate}
\item 6400\,km\label{item:earth}
\item Seven\label{item:dwarfs}
\end{enumerate}

\end{document}