Xiaojun reads a book, and reads (2/3) of this book in 7 days, and reads a total of 40 pages in the next 5 days, which is just finished. How many pages does this book have?
小军读一本书，7天读了这本书的(2/3)，以后5天共读40页，正好读完．这本书有多少页？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">40 / (1/3)</gadget>
<output>120</output>

<result>120</result>