One job is done by A alone in 10 hours, B by himself in 12 hours, and C by himself in 15 hours. How many hours can three people work together to complete this job (3/4)? How many
一件工作，甲独做10小时完成，乙独做12小时完成，丙独做15小时完成．三人合做几小时可以完成这件工作的(3/4)？多少
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

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

<gadget id="calculator">(1/10) + (1/12) + (1/15)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(3/4) / (1/4)</gadget>
<output>3</output>

<result>3</result>