The computer company needs 420 computers, 20 of which have already been installed, and the remaining 25 are assembled every day. How many days will it take to finish the installation?
电脑公司要420台电脑，已经装20台，剩下的每天装配25台，还要几天才能装完？
<gadget id="calculator">420 - 20</gadget>
<output>400</output>

<gadget id="calculator">400 / 25</gadget>
<output>16</output>

<result>16</result>