Insert a 2.8-meter-long bamboo pole into the pool, (1/7) is exposed to the water, and (1/4) of the remaining bamboo pole is inserted into the mud. How deep is the pool?
将一根长2.8米的竹竿插入池中，(1/7)露出水面，剩余竹竿的(1/4)插在泥里，问池深多少米？
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 - (1/7)</gadget>
<output>6/7 = around 0.857143</output>

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

<gadget id="calculator">1 - (1/4)</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">2.8 * (6/7) * (3/4)</gadget>
<output>1.8</output>

<result>1.8</result>