There are 300 books in the two bookshelves A and B, take out (1/3) from A bookshelf and put them in B bookshelf, and then take out 30 books from B bookshelf and put them in A bookshelf, then the books on the two bookshelves are equal, and the books in A bookshelf How many copies?
甲、乙两个书架共有书300本，由甲书架取出(1/3)放入乙书架，再由乙书架取出30本放入甲书架，则两个书架的书相等，甲书架原有书多少本？
<gadget id="calculator">300 - 30 - 30</gadget>
<output>240</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3) - (1/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 + (1/3)</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">240 / (4/3)</gadget>
<output>180</output>

<result>180</result>