Cylinder C has 3 $$l$$ of water. <br> Cylinder D has 7 $$l$$ of water. <br>Water is poured into Cylinder C until both Cylinder C and D have the same amount of water. <hr> <input min="0" type="number" id ="imp2pg225q1_1" class="lineinput" placeholder="?" /> $$l$$ of water is poured into Cylinder C.