A bag of rice, 40% of it was eaten in the first week, 15 kg in the second week, and there are 9 kg left. How many kg is the bag of rice?
一袋米，第一周吃了40%，第二周吃了15千克，还剩9千克，这袋米原来有多少千克？
<gadget id="calculator">15 + 9</gadget>
<output>24</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">24 / (3/5)</gadget>
<output>40</output>

<result>40</result>