Xiaoqiang reads a book. He reads (1/3) of the total pages in the first week and (1/5) of the total pages in the second week. What percentage of the book has he not read?
小强读一本书，第一周读了总页数的(1/3)，第二周读了总页数的(1/5)，剩下这本书的几分之几没有读？
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

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

<gadget id="calculator">1 - (1/3) - (1/5)</gadget>
<output>7/15 = around 0.466667</output>

<result>7/15 = around 0.466667</result>