A cup of salt water, the salt accounts for (1/5) of the salt water, and after adding 16 grams of salt, the salt accounts for (1/4) of the salt water, how many grams of the original salt water.
一杯盐水，盐占盐水的(1/5)，再加入16克盐后，盐占盐水的(1/4)，原来盐水有多少克．
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">4 / 5</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(1/5) / (4/5) / (3/4)</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/5) / (4/5)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/3) - (1/4)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">16 / (1/12) / (4/5)</gadget>
<output>240</output>

<result>240</result>