Marie has 4 x 20 = <<4*20=80>>80 stamps from her notebooks.
And she has 2 x 50 = <<2*50=100>>100 stamps from her binders.
So she has a total of 80 + 100 = <<80+100=180>>180 stamps.
Marie decided to keep 180 x 1/4 = <<180*1/4=45>>45 stamps only.
Therefore, she can give away 180 - 45 = <<180-45=135>>135 stamps.
#### 135