A rectangular piece of carpet is placed on the floor of a function room leaving a margin of 1 metre around it.<br>The room measures 31 m by 18 m. If the cost of the carpet is $21 per $$m^2$$<hr>The cost to carpet the whole room is $ <input min="0" type="number" id ="imp5pg008q11_1" class="lineinput" placeholder="?" />.