In 1998, a catastrophic flood occurred in the Yangtze River Basin in my country, and the military and civilians all over the country actively participated in the fight against the flood. In order to strengthen the embankment, wooden piles need to be driven into the river. One flood control wooden pile is (7/3) meters long. In the mud. Excuse me, how deep is the river?
1998年我国长江流域发生了特大洪水，全国军民积极投入到抗洪战斗中去．为了加固河堤，需向河中打入木桩，一根防洪木桩长(7/3)米，砸入水中后，(1/5)露出水面，其余的(2/7)在河底的淤泥中．请问，河水有多深？
<gadget id="calculator">7 / 3</gadget>
<output>7/3 = around 2.333333</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 - (1/5) - (2/7)</gadget>
<output>18/35 = around 0.514286</output>

<gadget id="calculator">(7/3) * (18/35)</gadget>
<output>6/5 = around 1.2</output>

<result>6/5 = around 1.2</result>