Xiao Ming reads a 160-page story book. He reads (2/5) of the whole book on the first day and (1/3) on the second day. What fraction of the whole book is left?
小明看一本160页的故事书，第一天看了全书的(2/5)，第二天看了(1/3)，还剩下全书的几分之几？
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

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

<gadget id="calculator">1 - (2/5) - (1/3)</gadget>
<output>4/15 = around 0.266667</output>

<result>4/15 = around 0.266667</result>