Suppress page number from Chapter side titlesec

Question

I'm struggling with removing/suppressing the page number from pages with chapter headings. When using \usepackage[pagestyles]{titlesec} and

 \newpagestyle{mystylep}{ 
    \setfoot{}{}{}}

the page number on pages with only text is suppressed, but still appears on pages with chapter headings.. The pagestyle is used fro the Preface and Problem Description, right before the Abstract..

for the main text i use:

\newpagestyle{mystyle}{ 
    \sethead[][][\chaptertitle]{\chaptertitle}{}{} 
    \setheadrule{.4pt} 
    \setfoot{}{\thepage}{}}

and for the appendix:

\newpagestyle{mystylea}{ 
    \setfoot{}{\thepage}{}

I only like to take away the page number on pages with chapter heading in mystylep pages..

EDIT:

\titleformat{\chapter}[block] 
    {\normalfont\huge\bfseries}{\thechapter}{20pt}{\Huge} 
\titlespacing*{\chapter}{0pt}{50pt}{40pt} 

%Main
\newpagestyle{mystyle}{ 
    \sethead[][][\chaptertitle]{\chaptertitle}{}{} 
    \setheadrule{.4pt} 
    \setfoot{}{\thepage}{}} 

%App
\newpagestyle{mystylea}{ 
    \setfoot{}{\thepage}{}} 

%Pre
\newpagestyle{mystylep}{ 
    \setfoot{}{}{}}

and:

\documentclass[pdftex,10pt,b5paper,twoside]{report}
\usepackage[lmargin=25mm,rmargin=25mm,tmargin=27mm,bmargin=30mm]{geometry}
\usepackage{hyperref}
\usepackage[pagestyles]{titlesec}

\begin{document}
\pagenumbering{alph}
\pagestyle{mystylep}
\assignpagestyle{\chapter}{empty}
%\maketitle
\hypersetup{pageanchor=false}
\include{problem}
\include{abs}
\hypersetup{pageanchor=true}
\pagenumbering{roman}               
\pagestyle{mystyle}
\tableofcontents
\listoffigures
\listoftables
\end{document}

problem.tex

\chapter*{Problem Description}

Text text text text text ..............

\vspace{1in}

\noindent
Assignment given: date
\\
Supervisor: NAME

abs.tex

\begin{abstract}
text text text text ........
\end{abstract}

Answer 1

This is as easy as:

\assignpagestyle{\chapter}{empty}

This is explained on page 7 (section 3.5) of the titlesec manual.

Edit

A quick fix for the actual problem seems to be to put \thispagestyle{empty} just after your \chapter command.