The electronics factory plans to assemble a batch of computers. It plans to assemble 28 computers per day and complete the task in 30 days. The task is actually completed 9 days ahead of schedule. How many computers are actually assembled per day?
电子厂计划装配一批电脑，计划每天装配28台，30天完成任务，实际提前了9天完成任务，实际每天装配多少台？
<gadget id="calculator">30 - 9</gadget>
<output>21</output>

<gadget id="calculator">30 / 21</gadget>
<output>10/7 = around 1.428571</output>

<gadget id="calculator">28 * (10/7)</gadget>
<output>40</output>

<result>40</result>