The weight of the child's mother is between 45 and 50 kilograms, which is exactly 7 times the child's weight. What is the child's weight in kilograms?
小孩妈妈的体重在45～50千克之间，正好是小孩体重的7倍，小孩的体重是多少千克．
<gadget id="calculator">49 / 7</gadget>
<output>7</output>

<result>7</result>