A cuboid water tank is filled with (2/5) tanks of water, exactly 140 liters. It is known that the bottom of the water tank is a square with a side length of 5 decimeters. What is the height of the water tank? (The thickness of the tank is ignored)
一个长方体水箱，里面装了(2/5)箱水，正好是140升．已知水箱的底面是边长为5分米的正方形，这个水箱的高度是多少？(水箱的厚度忽略不计)
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">140 / (2/5)</gadget>
<output>350</output>

<gadget id="calculator">5 * 5</gadget>
<output>25</output>

<gadget id="calculator">350 / 25</gadget>
<output>14</output>

<result>14</result>