There are two bookshelves, A and B, it is known that A bookshelf has 800 books, borrowed from A bookshelf (1/4), after borrowing 45% from B bookshelf, A bookshelf is 5 times more than B bookshelf 50 books, B bookshelf originally How many copies are there?
甲、乙两个书架，已知甲书架有800本，从甲书架借出(1/4)，从乙书架借出45%以后，甲书架是乙书架的5倍多50本，乙书架原有多少本？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">800 * (3/4)</gadget>
<output>600</output>

<gadget id="calculator">600 - 50</gadget>
<output>550</output>

<gadget id="calculator">550 / 5</gadget>
<output>110</output>

<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">1 - (9/20)</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">110 / (11/20)</gadget>
<output>200</output>

<result>200</result>