Xiaohong's family has some rice. Dad said: "20% of it has been eaten." Mom said: "If you buy another 30 kilograms, it will be the same as before." How many kilograms of rice did Xiaohong's family originally have?
小红家有一些大米，爸爸说："已经吃了20%，"妈妈说："如果再买进30千克，就和原来一样多．"小红家原来有多少千克大米？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">30 / (1/5)</gadget>
<output>150</output>

<result>150</result>