project can be completed by A alone in 10 hours, and B alone can complete (1/4) of the project in 3 hours. If A and B work together for 2 hours, and then A works alone, how many hours will it take to complete the project?
一项工程，甲独做10小时完成，乙独做3小时可完成这项工程的(1/4)．如果甲乙合做2小时后，再由甲独做，还要几小时可完成这项工程？
<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) / 3</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(1/10) + (1/12)</gadget>
<output>11/60 = around 0.183333</output>

<gadget id="calculator">(11/60) * 2</gadget>
<output>11/30 = around 0.366667</output>

<gadget id="calculator">1 - (11/30)</gadget>
<output>19/30 = around 0.633333</output>

<gadget id="calculator">(19/30) / (1/10)</gadget>
<output>19/3 = around 6.333333</output>

<result>19/3 = around 6.333333</result>