find the height of wall

Area of four walls = Total cost / 10

                                         =  15000/ 10

                                         = 1500 sq. m

  perimeter of the floor =  2(l +b)

                                         = 250m

 Now area of four walls = 2 (l + b)h

                    1500 =  250.h

   h = 1500 /250

      = 6 m

Therefore  height of wall = 6 m