There was a batch of storybooks in the school library. After senior students borrowed 40%, the administrator bought another 180 from Xinhua Bookstore. The newly bought storybooks were just equivalent to 25% of the previous batch. How many storybooks did the grade student borrow?
学校图书馆原有一批故事书，高年级学生借走40%后，管理员又从新华书店买来180本，新买来的故事书刚好相当于借走前这批故事书的25%，高年级学生借走故事书多少本？
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">180 / (1/4)</gadget>
<output>720</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">720 * (2/5)</gadget>
<output>288</output>

<result>288</result>