Iris and his brother and sister were able to pick a total of 30 + 20 + 10 = <<30+20+10=60>>60 berries.
The rotten berries that needed to be thrown away are (1/3) x 60 = <<(1/3)*60=20>>20.
So, the total number of fresh berries is 60 - 20 = <<60-20=40>>40.
The berries they need to keep are (1/2) x 40 = <<(1/2)*40=20>>20.
Therefore, the total number of berries they will be able to sell is 40 - 20 = <<40-20=20>>20.
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