Fresh mutton has only its original weight (13/20) after being cooked. To process 260 grams of cooked mutton, how many grams of fresh mutton are needed?
鲜羊肉煮熟后只有它原重量的(13/20)，要加工熟羊肉260克，需要鲜羊肉多少克？
<gadget id="calculator">13 / 20</gadget>
<output>13/20 = around 0.65</output>

<gadget id="calculator">260 / (13/20)</gadget>
<output>400</output>

<result>400</result>