The sum of the ages of the parents this year is 78, and the sum of the ages of the two brothers is 17. Four years later, the age of the father will be four times the age of the brother, and the age of the mother will be three times the age of the brother. So starting from this year, how much Years later, the age of the father is three times the age of the brother.
今年父母的年龄和是78岁，兄弟俩的年龄和是17岁，四年后父的年龄是弟的年龄的4倍，母的年龄是兄的年龄的3倍，那么从今年开始计，多少年后父的年龄是兄的年龄的3倍．
<gadget id="calculator">17 + 4 + 4</gadget>
<output>25</output>

<gadget id="calculator">25 * 4</gadget>
<output>100</output>

<gadget id="calculator">78 + 4 + 4</gadget>
<output>86</output>

<gadget id="calculator">100 - 86</gadget>
<output>14</output>

<gadget id="calculator">4 - 3</gadget>
<output>1</output>

<gadget id="calculator">14 / 1</gadget>
<output>14</output>

<gadget id="calculator">25 - 14</gadget>
<output>11</output>

<gadget id="calculator">11 * 4</gadget>
<output>44</output>

<gadget id="calculator">44 - 4</gadget>
<output>40</output>

<gadget id="calculator">14 - 4</gadget>
<output>10</output>

<gadget id="calculator">40 - 10</gadget>
<output>30</output>

<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">15 - 10</gadget>
<output>5</output>

<result>5</result>