\documentclass[10pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage{graphicx,verbatim,hyperref} %graphicx allows you to insert images, although when I was in first year I just left large blank spaces, sometimes by inserting a blank image, and then drew pictures. Verbatim allows you to comment with "\begin{comment} and \end{comment}". Hyperref puts hyperlinks in the pdf, which isn't actually very useful for assignments (so feel free to leave it out) but is very useful for longer documents like lecture notes and theses.
%\usepackage[left=2cm,right=2cm,top=2cm,bottom=2cm]{geometry}
\usepackage{amsmath,amsfonts,amssymb,amsthm}
%The following are quite useful overall so I tend to leave them in all the time, but probably won't be used much for assignments
\newtheorem{thm}{Theorem}[]
\newtheorem{cor}[thm]{Corollary}
\newtheorem{lem}[thm]{Lemma}
\newtheorem{conj}[thm]{Conjecture}
\newtheorem{prop}[thm]{Proposition}
\newtheorem{prob}[thm]{Problem} %this one is quite useful for assignments. Instead of the word "problem" you could write "Answer" or "Question" or whatever you like.
\theoremstyle{remark}
\newtheorem{rem}[thm]{Remark}
\newtheorem{ans}[thm]{Answer}
\newtheorem*{note}{Note}
\theoremstyle{definition}
\newtheorem{defin}[thm]{Definition}
\newtheorem{ques}[thm]{Question}
%The following are commands I have defined to make my life easier.
\newcommand{\N}{\mathbb{N}}
\newcommand{\Z}{\mathbb{Z}}
\newcommand{\Q}{\mathbb{Q}}
\newcommand{\R}{\mathbb{R}}
\newcommand{\C}{\mathbb{C}}
\newcommand{\Power}{\mathcal{P}}
\author{Michelle Strumila \\ 23456789 }
\title{Assignment 2}
\begin{document}
\maketitle
\begin{prob}[Optional title]
Here is a description of a problem, or perhaps the answer to a problem. Maybe we are trying to prove that $\mathcal{P}(X \cap Y) = \mathcal{P}(X) \cap \Power (Y)$
\end{prob}
\begin{proof}
Here is a proof.
\begin{align*}
x & \in \Power(X \cap Y) \\
x & \subseteq (X \cap Y) \\
\ldots
\end{align*}
\end{proof}
Or alternatively, you could do something like:
\begin{prob}
Here is my answer to question 2. It involves the integers, $\Z$ which can also be typed as $\mathbb{Z}$.
\end{prob}
\begin{ans}
Here is my answer to question 3. It involves the integers, $\Z$ which can also be typed as $\mathbb{Z}$.
\end{ans}
\begin{ques}
Here is my answer to question 4. It involves the integers, $\Z$ which can also be typed as $\mathbb{Z}$.
\end{ques}
\end{document}