There is a bag of rice, 40% of it was eaten in the first week, and 18 kg was just finished in the second week. How many kilograms is this bag of rice originally?
有一袋大米，第一周吃了40%，第二周吃了18千克刚好吃完．这袋大米原有多少千克？
<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>