Liu Yue asked Xiao Hai's father: "How old is Xiao Hai this year?" Xiao Hai's father said to Liu Yue: "Xiao Hai's age this year is mine (1/5), after 12 years, Xiao Hai's age will be mine (3/5) 7)."Students, do you know how old Xiao Hai is?
柳月问小海的父亲："小海今年多大了？"小海的父亲对柳月说："小海今年的年龄是我的(1/5)，12年后，小海的年龄将是我的(3/7)．"同学们，你们知道小海今年多少岁吗？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">3 / 7</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">(3/7) * 12</gadget>
<output>36/7 = around 5.142857</output>

<gadget id="calculator">12 - (36/7)</gadget>
<output>48/7 = around 6.857143</output>

<gadget id="calculator">(3/7) - (1/5)</gadget>
<output>8/35 = around 0.228571</output>

<gadget id="calculator">(48/7) / (8/35)</gadget>
<output>30</output>

<gadget id="calculator">(1/5) * 30</gadget>
<output>6</output>

<result>6</result>