A bag of rice was eaten (1/5) on the first day and 30 kilograms on the second day, and (1/2) of the bag of rice was eaten in two days. How many kilograms of this bag of rice are there?
一袋大米，第一天吃了(1/5)，第二天吃了30千克，两天共吃去这袋大米的(1/2)，这袋大米共有多少千克？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/2) - (1/5)</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">30 / (3/10)</gadget>
<output>100</output>

<result>100</result>