On scale drawing the scale is 1 and 4 inch = 1 foot . what are the dimensions on the scale drawing for a room that is 15 feet by 16 feet

The answer is:  

      The dimensions are:  "3.75 in. by 4 in."
  {that correspond to a room that is "15 feet by 16 feet", respectively.}.

Explanation:

   The scale is:  0.25 in : 1 ft.

0.25 in /1 ft= x  in /15 ft ;  x = (0.25)*(15) in. = 3.75 in. ;


0.25 in/ 1 ft = x in/ 16 ft ;    x  =   (0.25)*(16) in.
                                              =   (¼)*(16) in.  =  (16/4) in.
                                              =  4 in. ;

So, the answer is:  The dimensions are "3.75 in. by 4 in."
   {that correspond to a room that is 15 feet by 16 feet, respectively.}.

A=17 B=23 and C. Can only be determined if you know the answer to X.