job can be completed in 8 days alone, B can be completed in 12 days alone, and C can be completed in 15 days alone. Now the three work together, because B is sick and rests for a few days, so it is not completed until the fifth day. How many days does B rest? (column solution)
一件工作甲独做8天完成，乙独做12天完成，丙独做15天完成，现在三人合作，因为乙病中途休息几天，这样到第5天才完成，乙休息了几天？(列式解答)
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

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

<gadget id="calculator">(1/8) + (1/15)</gadget>
<output>23/120 = around 0.191667</output>

<gadget id="calculator">(23/120) * 5</gadget>
<output>23/24 = around 0.958333</output>

<gadget id="calculator">1 - (23/24)</gadget>
<output>1/24 = around 0.041667</output>

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

<gadget id="calculator">(1/24) / (1/12)</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">5 - (1/2)</gadget>
<output>9/2 = around 4.5</output>

<result>9/2 = around 4.5</result>