It is planned to install 120 TV sets. If 8 sets are installed every day, the task can be completed 1 day earlier than planned. Now the task is completed 4 days earlier than planned. How many sets should be installed every day?
计划装120台电视机，如果每天装8台可比计划提前1天完成任务，现在要比计划提前4天完成任务，每天应装多少台？
<gadget id="calculator">120 / 8</gadget>
<output>15</output>

<gadget id="calculator">15 + 1</gadget>
<output>16</output>

<gadget id="calculator">16 - 4</gadget>
<output>12</output>

<gadget id="calculator">120 / 12</gadget>
<output>10</output>

<result>10</result>