The mass ratio of Type A candy to Type B candy is 1:3, and 20 kg of Type A candy is added later. At this time, the mass ratio of Type A candy to Type B candy is 3:5. How many kilograms of Type A candy at this time ?
现有甲种糖果与乙种糖果质量比为1：3，后来又添进甲种糖果20千克，这时甲种糖果与乙种糖果质量比为3：5，问此时甲种糖果多少千克？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(3/5) - (1/3)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">20 / (4/15)</gadget>
<output>75</output>

<gadget id="calculator">75 * (3/5)</gadget>
<output>45</output>

<result>45</result>