After 40% of a bag of rice is used, there is 15 kilograms left. How many kilograms does this bag of rice originally weigh? (column equation solution)
一袋大米，用去40%后，剩下15千克，这袋大米原来有多少千克？(列方程解答)
<gadget id="calculator">1 - 0.4</gadget>
<output>0.6</output>

<gadget id="calculator">15 / 0.6</gadget>
<output>25</output>

<result>25</result>