A batch of cement is shipped from a construction site. (5/7) tons are used for building walls, (7/8) tons are used for mopping the ground, and (5/6) tons are left. How many tons are there in this batch of cement?
某建筑工地运来一批水泥，砌墙用去了(5/7)吨，抹地用去了(7/8)吨，还剩(5/6)吨，这批水泥共有多少吨？
<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">7 / 8</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">(5/7) + (7/8) + (5/6)</gadget>
<output>407/168 = around 2.422619</output>

<result>407/168 = around 2.422619</result>