There is a bag of rice, 40% of it is taken out for the first time, and 3 kg more than the first time is taken out for the second time, leaving 15 kg. How many kilograms does this bag of rice weigh?
有一袋米，第一次取出它的40%，第二次比第一次多取3千克，还剩下15千克．原来这袋米重多少千克？
<gadget id="calculator">15 + 3</gadget>
<output>18</output>

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

<gadget id="calculator">1 - (2/5) - (2/5)</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">18 / (1/5)</gadget>
<output>90</output>

<result>90</result>