The weight of chocolate is three times that of toffee. If 15 kilograms are taken out of chocolate and poured into toffee, then the weight of the two kinds of sugar is equal. How many kilograms of chocolate are there?
巧克力的重量是奶糖的3倍，如果从巧克力中取出15千克倒入奶糖中，那么两种糖的重量就相等了，巧克力有多少千克．
<gadget id="calculator">15 * 2</gadget>
<output>30</output>

<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">30 / 2</gadget>
<output>15</output>

<gadget id="calculator">15 * 3</gadget>
<output>45</output>

<result>45</result>