There are 5 lions in the zoo, with a total weight of 900 kg. On average, the weight of each lion is exactly 9 times that of a lamb. How many kilograms does this lamb weigh?
动物园里有5只狮子，体重一共是900千克，平均每只狮子的体重恰好是一只小羊的9倍．这只小羊体重是多少千克？
<gadget id="calculator">900 / 5 / 9</gadget>
<output>20</output>

<result>20</result>