Buying A and B two different candies, the cost ratio is 4:5. It is known that Type A candy is 8 yuan per kilogram, and Type B candy is 5 yuan per kilogram. If these two kinds of candies are mixed together to make assorted candies, what is the cost price per kilogram of assorted candies?
购进甲、乙两种不同糖果，费用之比是4：5．已知甲种糖果每千克8元，乙种糖果每千克5元．如把这两种糖果混在一起成为什锦糖，那么什锦糖每千克的成本价是多少元．
<gadget id="calculator">40 + 50</gadget>
<output>90</output>

<gadget id="calculator">40 / 8</gadget>
<output>5</output>

<gadget id="calculator">50 / 5</gadget>
<output>10</output>

<gadget id="calculator">5 + 10</gadget>
<output>15</output>

<gadget id="calculator">90 / 15</gadget>
<output>6</output>

<result>6</result>