Find the area of the room by multiplying the length by the width:
Area of room = 15.5 x 18.5 = 286.75 square feet.
Divide the total area of the room by the area of a box to find the number of boxes needed.
286.75 / 25 = 11.47
Since you can't buy a partial box, round up to the nearest whole number.
You need B. 12 boxes total.