There are 16 curlers in all and ¼ of them are pink or 16 curlers / 4 = <<16/4=4>>4 pink curlers.
There are twice as many blue curlers as there are pink ones, so there are 4 pink x 2 = <<4*2=8>>8 blue curlers.
Together, there are 4 pink curlers + 8 blue curlers = <<4+8=12>>12 pink and blue curlers in Erin’s hair.
The remaining curlers are green, so of the 16 total curlers – 12 pink and blue curlers = <<4=4>>4 green curlers are in Erin’s hair.
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