Teams A, B, and C are working together to build a canal. Team A has built 2/5 of the full length, Team B has built 1/3 of the full length, and what fraction of the full length has Team C built?
甲、乙、丙三队合修一条水渠，甲队修了全长的(2/5)，乙队修了全长的(1/3)，丙队修了全长的几分之几？
<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>