                                                                                                                                                            
 \documentclass{exam}                                                                                                                                       
 \usepackage{amsmath}                                                                                                                                       
 \usepackage{multicol}                                                                                                                                      
                                                                                                                                                            
 \begin{document}                                                                                                                                           
 \begin{questions}                                                                                                                                          
