"Husband and wife lung slices" is a famous dish in Sichuan. The main ingredients are beef, tripe and beef louver. The unit price of each kilogram is 21 yuan, 29 yuan, and 28 yuan respectively. These three ingredients are mixed with the same weight." "Couple's lung slice", how much should the price be per kilogram?
"夫妻肺片"是四川的一道名菜，主要选料有牛肉，牛肚和牛百叶，它们每千克的单价分别为21元、29元、28元，把这三样选取同样重量混合制成"夫妻肺片"，每千克应售价多少元？
<gadget id="calculator">21 + 29 + 28</gadget>
<output>78</output>

<gadget id="calculator">1 + 1 + 1</gadget>
<output>3</output>

<gadget id="calculator">78 / 3</gadget>
<output>26</output>

<result>26</result>