The ratio of money between Uncle He and Chen is 7:5. If Uncle He gives Uncle Chen 65 yuan, the ratio of money between them will become 3:4. Ask how much money Uncle He has.
何、陈两位叔叔身上原有钱数之比是7：5，如果何叔叔给陈叔叔65元，那么他们的钱数之比就变为3：4．问原来何叔叔有多少元钱．
<gadget id="calculator">7 + 5</gadget>
<output>12</output>

<gadget id="calculator">7 / 12</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">3 + 4</gadget>
<output>7</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">(7/12) - (3/7)</gadget>
<output>13/84 = around 0.154762</output>

<gadget id="calculator">65 / (13/84)</gadget>
<output>420</output>

<gadget id="calculator">420 * (7/12)</gadget>
<output>245</output>

<result>245</result>