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There are a total of 7 + 2 + 1 = 10 marbles in the bag.
Marbles that are not blue include the 7 red marbles and the 1 green marble, which is a total of 7 + 1 = <<7+1=8>>8 marbles.
The probability of choosing a marble that is not blue is 8 / 10 = <<8/10=0.8>>0.8, or 80%. Answer: \boxed{0.8}.