Xiao Ming reads a book, first reads (1/4) of the whole book, and then reads 12 pages. At this time, the ratio of the pages he has read to the pages he has not read is 1:2. How many pages does this book have?
小明看一本书，先看了全书的(1/4)，又看了12页，这时已看的与未看的比是1：2，这本书有多少页？
<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/3) - (1/4)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">12 / (1/12)</gadget>
<output>144</output>

<result>144</result>