It takes 12 hours for A to complete a manuscript alone, and 15 hours for B to complete it alone. B first typed for 5 hours, and A continued to type the remaining manuscripts. How many hours will it take to finish?
打一份稿件，甲单独完成需要12小时，乙单独完成需要15小时．乙先打了5小时，剩下的稿件由甲接着打，还要几小时才能完成？
<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/15) * 5</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

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

<gadget id="calculator">(2/3) / (1/12)</gadget>
<output>8</output>

<result>8</result>