The fruit shop sells 20 kg of apples on the first day, 1/4 of the total mass of apples on the second day, and 50% of the sum of the previous two days on the third day, leaving 5 kg unsold. How many kilograms does this batch of apples weigh?
水果店第一天卖出苹果20千克，第二天卖出苹果总质量的(1/4)，第三天卖出前两天总和的50%，还剩下5千克没有卖．这批苹果有多少千克？
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">20 * (1/2)</gadget>
<output>10</output>

<gadget id="calculator">5 + 20 + 10</gadget>
<output>35</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(1/4) * (1/2)</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 - (1/4) - (1/8)</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">35 / (5/8)</gadget>
<output>56</output>

<result>56</result>