One bag of 50 grams of tea can be exchanged for two bags of 500 grams of salt, so how many bags of 50 grams of tea can be exchanged for 20 bags of 500 grams of salt.
1袋50克的茶叶，可以换两袋500克的食盐，那么20袋500克的食盐可以换多少袋50克的茶叶．
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<result>10</result>