There are A, B, C, and D. A is 36 years old this year, and B, C, and D are all 10 years old. After how many years, A's age will be equal to the sum of the ages of B, C, and D?
有甲、乙、丙、丁，甲今年36岁，乙、丙、丁都是10岁，几年后甲的年龄等于乙、丙、丁三人的年龄之和？
<gadget id="calculator">10 * 3</gadget>
<output>30</output>

<gadget id="calculator">36 - 30</gadget>
<output>6</output>

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

<gadget id="calculator">6 / 2</gadget>
<output>3</output>

<result>3</result>