going to school

I live 7.9 miles away from school I travel an average of 40 mph

D                                      E                                       S                                A
                                 V=X/T                                 T=7.9                         
V=40mph                VT=X                                        .40                      19minutes
X=7.9 miles              T=X
T=?                                V
                                                                           
                                 T=7.9                                
                                      .40