Cynthia and Vivian went shopping for a present for their friend one day.<br>The ratio of the amount of money that Vivian paid to the amount of money that Cynthia paid was 2 : 9.<br>Vivian paid $12 for the present.<br> If the cost of the present were to be split equally, Vivian must return $<input min="0" type="number" id ="imp6pg097q6b_1" class="lineinput" placeholder="?" /> to Cynthia for the present?