There are three kinds of books in the book corner, story books account for 1/4 of the total, and the ratio of science books to the other two books is 2:5. There are 150 story books and science books in total. How many books are there in the book corner?
图书角有三种书，故事书占总数的(1/4)，科技书与其它两种书的比是2：5，故事书和科技书一共有150本，图书角一共有多少本书？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">2 + 5</gadget>
<output>7</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">(1/4) + (2/7)</gadget>
<output>15/28 = around 0.535714</output>

<gadget id="calculator">150 / (15/28)</gadget>
<output>280</output>

<result>280</result>