Lay a (6/7)km fiber optic cable, and lay the full length (7/8) in 3 days. How many kilometers are paved per day on average?
铺一条(6/7)km的光缆，3天铺了全长的(7/8)，平均每天铺多少km？
<gadget id="calculator">6 / 7</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">7 / 8</gadget>
<output>7/8 = around 0.875</output>

<gadget id="calculator">(7/8) / 3</gadget>
<output>7/24 = around 0.291667</output>

<gadget id="calculator">(6/7) * (7/24)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>