Two bottles of the same volume, A and B, are filled with salt water respectively. It is known that the ratio of salt to water in bottle A is 2:9, and the ratio of salt to water in bottle B is 3:10. Now put the two bottles of salt water in A and B What is the ratio of salt to brine in the mixed brine
甲、乙两个容积相同的瓶子分别装满盐水，已知甲瓶中盐、水的比是2：9，乙瓶中盐、水的比是3：10，现在把甲、乙两瓶盐水混合在一起，则混合盐水中，盐与盐水的比是多少
<gadget id="calculator">2 + 9</gadget>
<output>11</output>

<gadget id="calculator">2 / 11</gadget>
<output>2/11 = around 0.181818</output>

<gadget id="calculator">3 + 10</gadget>
<output>13</output>

<gadget id="calculator">3 / 13</gadget>
<output>3/13 = around 0.230769</output>

<gadget id="calculator">(2/11) + (3/13)</gadget>
<output>59/143 = around 0.412587</output>

<gadget id="calculator">(59/143) / 2</gadget>
<output>59/286 = around 0.206294</output>

<result>59/286 = around 0.206294</result>