A project can be completed in 15 days by A alone, and 18 days by B alone. Now, A works alone in 5 days. How many hours will it take for B to complete the rest?
一项工程，甲独做15天完成，乙独做18天完成，现由甲独做5天，余下的乙做，还要几小时完成？
<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 / 18</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">(2/3) / (1/18)</gadget>
<output>12</output>

<result>12</result>