Four years ago, the age of the mother was three times that of the daughter. This year, the combined age of the mother and daughter is 56. How old is the mother?
4年前，妈妈的年龄是女儿的3倍，今年母女俩的年龄之和是56，妈妈今年多少岁？
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">56 - 8</gadget>
<output>48</output>

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

<gadget id="calculator">48 / 4</gadget>
<output>12</output>

<gadget id="calculator">12 * 3</gadget>
<output>36</output>

<gadget id="calculator">36 + 4</gadget>
<output>40</output>

<result>40</result>