A book, Xiaoxin read the whole book (1/5) on the first day, the ratio of the number of pages read on the second day to the number of pages read on the first day is 2:3, and there are 120 pages left to read, this book How many pages does the book have?
一本书，小欣第一天读了全书的(1/5)，第二天读的页数与第一天读的页数的比是2：3，还剩120页没读，这本书一共有多少页？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(1/5) * (2/3)</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">(2/15) + (1/5)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">120 / (2/3)</gadget>
<output>180</output>

<result>180</result>