A sandwich and a pack of juice cost $0.3 + $0.2 = $<<0.3+0.2=0.50>>0.50.
With Lyle's $2.50, he can buy $2.50/$0.50 = <<2.5/0.5=5>>5 sets of sandwiches and juice.
Therefore, 5 - 1 = <<5-1=4>>4 of his friends can have a sandwich and a pack of juice since the other 1 set is for Lyle himself.
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