The milk production of three cows in a week is 18.9 kg. What is the milk production of one cow in a day?
三头奶牛一周的产奶量是18.9千克，问一头奶牛一天的产奶量是多少？
<gadget id="calculator">18.9 / 7 / 3</gadget>
<output>0.9</output>

<result>0.9</result>