Put 30 grams of salt in a glass of 120 grams of water, find the salt content of this glass of water.
在一杯120克水中放入30克的盐，求这杯水的含盐率．
<gadget id="calculator">120 + 30</gadget>
<output>150</output>

<gadget id="calculator">30 / 150</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

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

<result>1/5 = around 0.2</result>