The breeding group raised 72 hens and 9 roosters. The number of ducks is 6 times that of roosters, how many ducks are raised?
饲养组养了72只母鸡，9只公鸡．鸭的只数是公鸡的6倍，养鸭多少只？
<gadget id="calculator">6 * 9</gadget>
<output>54</output>

<result>54</result>