A cup of salt water, the ratio of salt to water is 1:15, then add 10 grams of salt, the ratio of salt to water in the new salt water is 1:9, find the mass of the current salt water.
一杯盐水，盐与水的比是1：15，再加入10克盐，新盐水中盐与水的比是1：9，求现在盐水的质量．
<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/9) - (1/15)</gadget>
<output>2/45 = around 0.044444</output>

<gadget id="calculator">10 / (2/45)</gadget>
<output>225</output>

<gadget id="calculator">1 + 9</gadget>
<output>10</output>

<gadget id="calculator">9 / 10</gadget>
<output>9/10 = around 0.9</output>

<gadget id="calculator">225 / (9/10)</gadget>
<output>250</output>

<result>250</result>