\documentclass{article}
\usepackage{graphicx}
\usepackage{subcaption}
\begin{document}
\begin{figure}
\begin{minipage}[b]{.4\textwidth}
\centering
\includegraphics[width=1.5in]{example-image-a}
\caption{This is first figure}
\end{minipage}%
\hfill
\begin{minipage}[b]{.5\textwidth}
\subcaptionbox{}{\includegraphics[width = 1in]{example-image-b}}
\subcaptionbox{}{\includegraphics[width = 1in]{example-image}}
\caption{caption}
\end{minipage}
\end{figure}
\end{document}

And an option using subfig:
\documentclass{article}
\usepackage{graphicx}
\usepackage{subfig}
\begin{document}
\begin{figure}
\begin{minipage}[b]{.4\linewidth}
\centering
\includegraphics[width=4cm]{example-image-a}
\caption{A figure}
\end{minipage}%
\begin{minipage}[b]{.6\linewidth}
\centering
\subfloat[subfigure]{\includegraphics[width=3cm]{example-image-b}}\quad
\subfloat[subfigure]{\includegraphics[width=3cm]{example-image-c}}
\caption{Another figure}
\end{minipage}
\end{figure}
\end{document}
