Xiao Ming reads a book. He reads 28 pages on the first day, (1/5) of the whole book on the second day, and (3/8) of the whole book in two days. How many pages does this book have?
小明看一本书，第一天看了28页，第二天看了全书的(1/5)，两天共看了全书的(3/8)，这本书共有多少页？
<gadget id="calculator">3 / 8</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(3/8) - (1/5)</gadget>
<output>7/40 = around 0.175</output>

<gadget id="calculator">28 / (7/40)</gadget>
<output>160</output>

<result>160</result>