Adam has a total of 50 balls - 20 red - 10 blue = <<50-20-10=20>>20 pink and orange balls combined
If we let x be the total number of orange balls, we know that 3x is the number of pink balls
Therefore, 20 balls = x + 3x = 4x
The number of orange balls, x, is 20 balls / 4 = <<20/4=5>>5 balls
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