
<PAGE>
 
           Statement Regarding Computation of Per Share Earnings

   Registrant's Basic and Diluted Earnings Per Share (in millions except
   per share amounts)

                                                            EXHIBIT 11
                                                            ----------
<TABLE> 
<CAPTION> 
                                                    Three months ended,
                                                        January 31
                                                    -------------------
                                                      1998      1997

<S>                                                 <C>         <C> 
Basic earnings per share

Net earnings                                          $929       $912

Number of shares on which basic earnings 
  per share is based:                             

Weighted-average common shares outstanding
  during the period                                  1,038      1,017  

Basic earnings per share                              $.89       $.90
                                                     =====      =====

Diluted earnings per share

Net earnings                                          $929       $912  
  Adjustment for interest expense, net of tax            6          -
                                                     -----      -----
  Net earnings, adjusted                               935        912
                                                         
Number of shares on which diluted earnings               
  per share is based:                                    
                                                         
Weighted-average common shares outstanding               
  during the period                                  1,038      1,017
                                                         
Weighted-average dilutive potential common shares:       
  Stock options                                         28         30
  Convertible zero-coupon notes due 2017                10          -
                                                         
Number of shares and equivalents on which                
  diluted earnings per share is based                1,076      1,047
                                                         
Diluted earnings per share                            $.86       $.87
                                                     =====      =====

</TABLE> 
