There are 25 footballs in the sports room, which is the total number of volleyballs and footballs (5/11). How many volleyballs are there?
体育室有足球25个，是排球和足球总个数的(5/11)，问排球有多少个？
<gadget id="calculator">5 / 11</gadget>
<output>5/11 = around 0.454545</output>

<gadget id="calculator">25 / (5/11)</gadget>
<output>55</output>

<gadget id="calculator">55 - 25</gadget>
<output>30</output>

<result>30</result>