Jane's mass is $$\frac{3}{7}$$ of Jack's mass. <hr> Find the ratio of Jane's mass to Jack's mass.<br> <input min="0" type="number" id="imp6pg084q8a_1" class="lineinput" placeholder="?"> : <input min="0" type="number" id="imp6pg084q8a_2" class="lineinput" placeholder="?">