There are 7 white balls and 24 yellow balls in the bag. How many white balls need to be added to make the ratio of white balls to yellow balls in the bag 5:3?
袋子里有白球7个，黄球24个，要使袋子里白球和黄球的个数比是5：3，需要增加多少个白球？
<result>43</result>