If some books are bundled into a bundle of 25 books, 60 bundles are required. If every 30 books are bundled into a bundle, how many bundles will be bundled? (Solve with ratio)
一些书如果每25本捆成一包，得捆60包．如果每30本捆成一包，得捆多少包？(用比例解)
<gadget id="calculator">25 * 60</gadget>
<output>1_500</output>

<gadget id="calculator">1_500 / 30</gadget>
<output>50</output>

<result>50</result>