Students stand in line to do exercises, stand in 40 rows, with 36 people in each row, if there are 72 people in each row, how many rows should they stand in?
同学们站队做操，站成40行，每行36人，如果每行72人，要站成多少行？
<gadget id="calculator">36 / 72</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">40 * (1/2)</gadget>
<output>20</output>

<result>20</result>