How to remove indent on non-item text inside an enumerated environment?

I'm using the enumerate environment to make a numbered list. I want to write a paragraph that serves as information for the next items. I want to remove the indent on this paragraph of text, so that it is indented just as much as the numbers in the list. How do I do this?

This is in essence what I've done. I've tried using \noindent, but without success.

\documentclass{book}

\begin{document}
\section*{Exercises}

Here are some exercises.

\begin{enumerate}
\item This is the first exercise.
\item This is the second exercise.

Here is some information to answer the questions below. This paragraph
should be indented just as much as the numbers in the list are.

\item This is the third exercise.
\item This is the fourth exercise.
\end{enumerate}
\end{document}

The output is:

-
possible duplicate of Resuming a list – mvkorpel Jul 3 '14 at 12:14
In my opinion, it is not a duplicate, because of the condition "This paragraph should be indented just as much as the numbers in the list are.". – T. Verron Jul 3 '14 at 12:57
@T.Verron I agree. I was too hasty. – mvkorpel Jul 3 '14 at 13:05
Thanks for the link, @mvkorpel. It partly solved my problem. However, as @T.Verron pointed out, I want the paragraph of text to be aligned with the numbers, not the section heading. I just used \hspace to shift it to the right place, but I'd really like to know of a better way. – vedadh Jul 3 '14 at 13:07
Good question. Upvoted. – mvkorpel Jul 3 '14 at 14:40

Here is a solution that uses the enumitem package: it has resume optional parameter and a series notion for enumerate environments. So I define a quest series, and an inform series, that are formatted so that the inform series leftmargin is exactly where labels of the quest series begin.

The information could be made of several paragraphs. I don't know if you want those after the first one to be indented. In my code they are; if you do not want this indentation, just remove listparindent=\parindent.

\documentclass{book}
\usepackage[utf8]{inputenc}
\usepackage{lipsum}
\usepackage{enumitem}

\begin{document}
\section*{Exercises}

Here are some exercises. Here are some exercises. Here are some exercises. Here are some exercises. Here are some exercises.

\begin{enumerate}[labelindent =\parindent, align = left, labelwidth =1em, leftmargin =! , labelsep =0.2 em, series = quest]
\item This is the first exercise. Quite a very very long exercise, with many questions and many more subquestions.
\item This is the second exercise.
\end{enumerate}

\begin{enumerate}[series = inform, leftmargin =\parindent, labelwidth =0pt, listparindent = \parindent]
\item[] Here is some information to answer the questions below. This paragraph
is indented just as much as the numbers in the list are.

Here is another information to answer the questions below. This paragraph is indented just as much as the numbers in the list are.
\end{enumerate}

\begin{enumerate}[resume* = quest]%
\item This is the third exercise.
\item This is the fourth exercise.
\end{enumerate}

\begin{enumerate}[resume*= inform]