Six years ago, the age of the mother was five times that of the son. After 6 years, the age sum of mother and child is 78 years old. Q: How old is your mother?
6年前，母亲的年龄是儿子的5倍．6年后母子年龄和是78岁．问：母亲今年多少岁？
<gadget id="calculator">6 * 2</gadget>
<output>12</output>

<gadget id="calculator">78 - 12</gadget>
<output>66</output>

<gadget id="calculator">66 - 12</gadget>
<output>54</output>

<gadget id="calculator">5 + 1</gadget>
<output>6</output>

<gadget id="calculator">54 / 6</gadget>
<output>9</output>

<gadget id="calculator">9 * 5</gadget>
<output>45</output>

<gadget id="calculator">45 + 6</gadget>
<output>51</output>

<result>51</result>