In the afternoon of the "Six Days" Festival, Li Xin led his friends to hold a "Love Charity Sale" activity in the Suguo Supermarket Plaza. He also used his beloved "365 Night Stories" as a charity sale product, with a total original price of 50 yuan. Once his bazaar price was 20 yuan, how much discount did he get for this bazaar?
"六一"节下午，李欣带领小伙伴们在苏果超市广场举行了"爱心义卖"活动，他把自己心爱的《365夜故事》上下册也作为了义卖商品，原价共50元，这一次他义卖价是20元，他的这份义卖商品打了几折？
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