Reading a book mischievously, I read (1/3) of the whole book on the first day, and the rest (1/4) on the second day, there are 80 pages left, how many pages are there in this book?
淘气看一本书，第一天看了全书的(1/3)，第二天又看了余下的(1/4)，还剩80页，这本书共有多少页．
<gadget id="calculator">1 / 3</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">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">(2/3) * (3/4)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">80 / (1/2)</gadget>
<output>160</output>

<result>160</result>