The candy store mixes 10 kilograms of toffee, 20 kilograms of halva and 30 kilograms of fruit sugar into assorted candies at 11.5 yuan per kilogram. Toffee is 15 yuan per kilogram, crisp candy is 12 yuan per kilogram, and what is the price per kilogram of fruit candy?
糖果店用10千克奶糖、20千克酥糖和30千克水果糖混合成每千克11.5元的什锦糖．奶糖每千克15元，酥糖每千克12元，水果糖每千克价钱是多少？
<gadget id="calculator">10 + 20 + 30</gadget>
<output>60</output>

<gadget id="calculator">60 * 11.5</gadget>
<output>690</output>

<gadget id="calculator">10 * 15</gadget>
<output>150</output>

<gadget id="calculator">20 * 12</gadget>
<output>240</output>

<gadget id="calculator">690 - 150 - 240</gadget>
<output>300</output>

<gadget id="calculator">300 / 30</gadget>
<output>10</output>

<result>10</result>