\documentclass{article}
\usepackage{amsmath}
\usepackage{graphicx}
\usepackage{caption}
\usepackage{subcaption}
%\usepackage{hyperref}
%\captionsetup{subrefformat=parens}
% new suref command
\newcommand{\suref}[2]{\figurename{} \ref{#1}:(\subref{#2})}
\begin{document}
\section{Simple figures}
\label{sec:simple}

This is a simple figure; see \figurename{} \ref{fig:fig-example}.
\begin{figure}[!htb]
  \centering
  \includegraphics[width=3.5in]{example-image-a}
  \caption{Figure's caption.}
  \label{fig:fig-example}
\end{figure}

\section{The subsigures option}
\label{sec:subfigures}
Now we are adding three sub-figure in one figure; see \figurename{} \ref{fig:three graphs}. Notice that in \ref{fig:a} ... or by using \suref{fig:three graphs}{fig:a} ... 

%on body
\begin{figure}
   \centering
   \begin{subfigure}[t]{0.3\textwidth}
       \centering
       \includegraphics[width=\textwidth]{example-image-a}
       \caption{The image a}
       \label{fig:a}
   \end{subfigure}
   \hfill
   \begin{subfigure}[t]{0.3\textwidth}
       \centering
       \includegraphics[width=\textwidth]{example-image-b}
       \caption{The image b}
       \label{fig:b}
   \end{subfigure}
   \hfill
   \begin{subfigure}[t]{0.3\textwidth}
       \centering
       \includegraphics[width=\textwidth]{example-image-c}
       \caption{The image c with more text than the other captions}
       \label{fig:c}
   \end{subfigure}
      \caption{Three images together and its large caption}
      \label{fig:three graphs}
    \end{figure}

\newpage

\section{Tables}
\label{sec:tables}


\end{document}