This year the age ratio of the grandson to the grandfather is 1:7, and the age of the grandson is 10 years old. How old is grandpa this year?
今年孙子和爷爷的年龄比是1：7，孙子的年龄是10岁．今年爷爷的年龄多少岁？
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">10 / (1/7)</gadget>
<output>70</output>

<result>70</result>