Each pack has 20/4 = <<20/4=5>>5 uncommons

So he got 10*5 = <<10*5=50>>50 uncommons

# Answer

50
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
John buys 10 packs of magic cards.  Each pack has 20 cards and 1/4 of those cards are uncommon.  How many uncommon cards did he get?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
50
John buys 10 packs of magic cards.  Each pack has 20 cards and 1/4 of those cards are uncommon.  How many uncommon cards did he get?
train