A rope was cut into 3 pieces.<br>The ratio of the length of the 3 pieces is 2 :4: 9. <hr> Express the length of the longest piece as a fraction of the lengt of the original rope.<br> $$\frac{A}{B}$$ <hr> A:<input min="0" type="number" id ="imp6pg085q1_1" class="lineinput" placeholder="?" /> B:<input min="0" type="number" id ="imp6pg085q1_2" class="lineinput" placeholder="?" />