Uncle Wang bound a batch of storybooks, originally planned to bind 50 books per hour, and he could complete the task on time. The actual binding is 60 books per hour, and the binding can be completed 2 hours in advance. How many books are there in total?
王叔叔装订一批故事书，原计划每小时装订50本，可以按时完成任务．实际每小时装订60本，可以提前2小时装订完．这批故事书共有多少本．
<gadget id="calculator">100 / 10</gadget>
<output>10</output>

<gadget id="calculator">10 * 60</gadget>
<output>600</output>

<result>600</result>