There are 120 roosters in a chicken farm, 40 more chicks than roosters, and three times as many hens as chicks. How many hens are there?
养鸡场有公鸡120只，小鸡比公鸡多40只，母鸡的只数是小鸡的3倍，母鸡有多少只？
<gadget id="calculator">120 + 40</gadget>
<output>160</output>

<gadget id="calculator">160 * 3</gadget>
<output>480</output>

<result>480</result>