There is a bridge pier, the part in the mud is the whole (1/4), the part in the water is the rest (3/5), the part above the water is 6 meters, how many meters is the height of this bridge pier?
有一桥墩，在泥中的部分是全部的(1/4)，在水中部分是其余的(3/5)，露出水面部分是6米，这个桥墩高是多少米？
<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">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(3/4) * (3/5)</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">1 - (1/4) - (9/20)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">6 / (3/10)</gadget>
<output>20</output>

<result>20</result>