The sum of mother and daughter's current age is 42 years old. After another 4 years, mother's age will be 1.5 times of her daughter's age. How old is her daughter now?
母女现在的年龄和是42岁，再过4年，母亲的年龄就是女儿的1.5倍，女儿现在多少岁．
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">42 + 8</gadget>
<output>50</output>

<gadget id="calculator">1.5 + 1</gadget>
<output>2.5</output>

<gadget id="calculator">50 / 2.5</gadget>
<output>20</output>

<gadget id="calculator">20 - 4</gadget>
<output>16</output>

<result>16</result>