format box around text like this?

Question

Can you help me format like this. Thank you so much!

Problem 1. Let ACB be a right-angled triangle with right angle CAB… (Problem is a counter)

Answer 1

you can start here....

(colors need to be changed...)

\documentclass{article}

\usepackage[most]{tcolorbox}

\newtcolorbox[auto counter
%,number within=section
]{pabox}[2][]{%
colback=red!5!white,
colbacktitle=red,
coltitle=red!70!black,
colframe=red!75!black,
fonttitle=\bfseries,
detach title,
before upper={\tcbtitle\quad},
title=Problem~\thetcbcounter. #2,#1}

\begin{document}

\begin{pabox}[]{}
This is a \textbf{tcolorbox}.
\end{pabox}

\end{document}

EDIT

\documentclass[border=3mm]{standalone}

\usepackage[most]{tcolorbox}

\newtcolorbox[auto counter
%,number within=section
]{pabox}[2][]{%
colback=green!90!blue,
%colbacktitle=black,
coltitle=black,
colframe=red!75!black,
fonttitle=\bfseries,
detach title,
bicolor,sidebyside,
righthand width=8cm,
colbacklower=blue!10,
before upper={\tcbtitle\quad},
title=Problem~\thetcbcounter. #2,#1}

\begin{document}

\begin{pabox}[]{}
\tcblower
This is a \textbf{tcolorbox}.
\end{pabox}

\end{document}