The grandma's family has 20 eggs, and she also raises an old hen that can lay one egg a day. If her family eats two eggs a day, how many days can the grandma's eggs last in a row?
老奶奶家有20个鸡蛋，还养了一天能下一个蛋的老母鸡，如果她家一天吃两个鸡蛋，老奶奶家的鸡蛋可以连续吃多少天．
<gadget id="calculator">2 - 1</gadget>
<output>1</output>

<gadget id="calculator">20 / 1</gadget>
<output>20</output>

<result>20</result>