The cafeteria used up a bag of rice in two days. On the first day, it used up 30% of the total amount. On the second day, it used 40 kilograms more than the first day. How many kilograms does this bag of rice contain?
食堂两天用完一袋大米，第一天用了全部的30%，第二比第一天多用40千克，求这袋大米有多少千克？
<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">1 - (3/10) - (3/10)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">40 / (2/5)</gadget>
<output>100</output>

<result>100</result>