A cow is 150 kg heavier than a dog, a sheep is 130 kg lighter than a cow, and the total weight of the three animals is 410 kg. What is the weight of a cow?
一头牛比一只狗重150千克，一只羊比一头牛轻130千克，三种动物共重410千克．求一头牛的重量是多少？
<gadget id="calculator">410 + 150 + 130</gadget>
<output>690</output>

<gadget id="calculator">690 / 3</gadget>
<output>230</output>

<result>230</result>