If a pile of sand is transported by a truck alone, it will take 10 times to be transported, and if it is transported by a small truck alone, it will be transported 15 times. Now that the truck and the small truck are transported together at the same time, how many times can it be transported completely?
一堆沙，如果由一辆卡车单独运要10次运完，如果由一辆小货车单独运要15次运完，现在卡车和小货车同时一起运，多少次可以全部运完？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/10) + (1/15)</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / (1/6)</gadget>
<output>6</output>

<result>6</result>