To determine the Ulices's account if he shipped just 1 box, calculate the charge for one box. To calculate the charge, compute the quotient between the charge for 4 boxes between 4 boxes, just as folow:
charge per one box = 140/4 = 35
Hence, for 1 box the charge is $35
Due to it is necessary to pay $20 idependenty of the number of boxex, you sum $20 to the cost for one box:
New Ulices's account = $35 + $20 = $55
Hence, Ulices's account would have been of $55