One day in math class, Lily asked the math teacher: "Teacher, how old are you?" The teacher replied: "This year I am three times your age. But 6 years ago I was five times your age. "What is the age of the math teacher now?"
一天在数学课上，莉莉问数学老师："老师，您多大岁数？"老师回答道："今年我的岁数是你现在年龄的3倍．但是6年前我的岁数是你当时年龄的5倍．"数学老师现在的年龄是多少岁．
<gadget id="calculator">6 * 5</gadget>
<output>30</output>

<gadget id="calculator">30 - 6</gadget>
<output>24</output>

<gadget id="calculator">5 - 3</gadget>
<output>2</output>

<gadget id="calculator">24 / 2</gadget>
<output>12</output>

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

<result>36</result>