A cubical container of edge 21 cm is filled with washing powder up to $$\frac{3}{7}$$ of its height. How much more washing powder can be poured into the container before it become full? Give your answer in litres and millilitres. (1 l= 1000 cm³) <br> <input min="0" type="number" id ="imp5pg232q10_1" class="lineinput" placeholder="?" /> $$l$$ <input min="0" type="number" id ="imp5pg232q10_2" class="lineinput" placeholder="?" /> ml