When Jiang Xiaoyun reads a book, he has read 40% of the whole book and there are 9 more pages. At this time, there are still 141 pages that he has not read. How many pages does this book have?
江小云看一本书，看了全书的40%还多9页，这时还有141页没看，这本书共有多少页？
<gadget id="calculator">141 + 9</gadget>
<output>150</output>

<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">150 / (3/5)</gadget>
<output>250</output>

<result>250</result>