A project, 12 workers 25 days to complete. If it takes 20 days to complete, how many workers are needed?
一项工程，12个工人25天完成．如果要20天完成，需要多少个工人？
<gadget id="calculator">25 / 20</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">12 * (5/4)</gadget>
<output>15</output>

<result>15</result>