cuboid tank measures 5 decimeters in length, 4 decimeters in width and 6 decimeters in height. Now pour 68 liters of water into the water tank, and then put a cylindrical steel material with a bottom area of 3 square decimeters and a height of 6 decimeters vertically into the water tank. The bottom surface of the steel billet is completely in contact with the bottom of the water tank. decimeter?
一个长方体水槽，从里面量得长5分米，宽4分米，高6分米．现往水槽里倒入68升水，再把一个底面积是3平方分米，高6分米的圆柱形钢材垂直放入水槽中，钢坯的底面与水槽的底部完全接触，此时水槽里水深多少分米？
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">68 / 20</gadget>
<output>17/5 = around 3.4</output>

<gadget id="calculator">(17/5) * 3</gadget>
<output>51/5 = around 10.2</output>

<gadget id="calculator">(51/5) / 20</gadget>
<output>51/100 = around 0.51</output>

<gadget id="calculator">(17/5) + (51/100)</gadget>
<output>391/100 = around 3.91</output>

<result>391/100 = around 3.91</result>