Xiaohong's father is 35 years old this year, and her mother is younger than her father (1/7). How old is her mother this year?
小红爸爸今年35岁，妈妈比爸爸小(1/7)，妈妈今年多少岁．
<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 - (1/7)</gadget>
<output>6/7 = around 0.857143</output>

<gadget id="calculator">35 * (6/7)</gadget>
<output>30</output>

<result>30</result>