Two boxes of fruit, if 3.2 kg is taken out of the first box and put into the second box, the weight of the two boxes is equal, and the weight of the first box is known to be 15 kg. How many kilograms is in the second box?
两箱水果，如果从第一箱中取出3.2千克放入第二箱，则两箱重量相等，已知第一箱重15千克．第二箱有多少千克？
<gadget id="calculator">3.2 * 2</gadget>
<output>6.4</output>

<gadget id="calculator">15 - 6.4</gadget>
<output>8.6</output>

<result>8.6</result>