To build a road, the full length (1/3) was repaired in the first week, the full length (2/5) was repaired in the second week, and the full length (7/8) was repaired after the third week. What fraction of the total length was repaired in the third week?
修一条路，第一周修了全长的(1/3)，第二周修了全长的(2/5)，第三周修完后，正好修完全长的(7/8)．第三周修了全长的几分之几？
<gadget id="calculator">7 / 8</gadget>
<output>7/8 = around 0.875</output>

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

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(7/8) - (1/3) - (2/5)</gadget>
<output>17/120 = around 0.141667</output>

<result>17/120 = around 0.141667</result>