Ryan has 40 balls. There are twice as many red balls as blue while the rest are green. If there are 11 blue balls, how many green balls are there?
There are 11 blue x 2 red/blue = <<11*2=22>>22 red balls.
The total number of blue and red balls is 11 blue + 22 red = <<11+22=33>>33 balls
There are 40 balls - 33 balls = <<40-33=7>>7 green balls.
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