Xiaoming's mother's weight is his father's (3/5), Xiaoming's weight is his mother's (1/3), Xiaoming's weight is 20 kilograms, what is his father's weight in kilograms.
小明妈妈的体重是爸爸的(3/5)，小明的体重是妈妈的(1/3)，小明的体重是20千克，爸爸的体重是多少千克．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">20 / (1/3) / (3/5)</gadget>
<output>100</output>

<result>100</result>