In a box, there were some red and blue marbles.<br>At first, the number of red marbles was $$\frac{3}{7}$$ of the number of blue marbles.<br>After 12 red marbles were taken out and 12 blue marbles were put into the box , the ratio of the number of red marbles to the number of blue marbles became 1 : 4. <hr> How many marbles were there in the box ? <br> <input min="0" type="number" id ="imp6pg091q3_1" class="lineinput" placeholder="?" />