The father is 32 years old this year, and the son is 4 years old. When the combined age of the father and son is 50 years old, how many years should it be?
爸爸今年是32岁，儿子是4岁，当父子俩年龄之和是50岁时，应该是几年之后的事？
<gadget id="calculator">32 + 4</gadget>
<output>36</output>

<gadget id="calculator">50 - 36</gadget>
<output>14</output>

<gadget id="calculator">14 / 2</gadget>
<output>7</output>

<result>7</result>