The binding team needs to bind 1680 books, and plans to bind 80 books per hour. If the task is to be completed 5 hours ahead of schedule, how many books should be bound per hour?
装订小组要装订1680本书，计划每小时装订80本，如果要提前5小时完成任务，那么每小时要装订多少本？
<gadget id="calculator">1_680 / 80</gadget>
<output>21</output>

<gadget id="calculator">21 - 5</gadget>
<output>16</output>

<gadget id="calculator">1_680 / 16</gadget>
<output>105</output>

<result>105</result>