Mingming’s family bought a bag of rice, ate 40% of it in the first week, ate 12kg in the second week, and left 6kg uneaten. How many kilograms did this bag of rice originally weigh?
明明家买了一袋米，第一周吃了40%，第二周吃了12kg，还有6kg没吃．这袋米原来有多少千克？
<gadget id="calculator">12 + 6</gadget>
<output>18</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">18 / (3/5)</gadget>
<output>30</output>

<result>30</result>