Xiaoxin reads a book and reads 40% of the whole book on the first day. I read the rest (5/9) the next day, and I read exactly 121 pages in two days. How many pages are there in the book?
小新看一本书，第一天看了全书的40%．第二天看了余下的(5/9)，两天正好看了121页，全书共有多少页？
<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">(3/5) * (5/9)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(2/5) + (1/3)</gadget>
<output>11/15 = around 0.733333</output>

<gadget id="calculator">121 / (11/15)</gadget>
<output>165</output>

<result>165</result>