Question 711150
1 feet = 12 inches
 height of first box = 6 feet 6 inches  = 6*12 + 6  = 78 inches
height of second box  = 4 feet 10 inches  = 4*12 + 10 
                                           = 48+10
                                            = 58 inches
  total height  = 78+58  =136 inches 
                           or  11 feet 4 inches