Magdalena picked 1/5 * 200 apples = <<1/5*200=40>>40 apples on the first day.
On the second day, she picked 2 * 40 apples = <<2*40=80>>80 apples from the tree
The total number of apples that he picked on the third day is 40 apples + 20 apples = <<40+20=60>>60 apples
In total, she picked 40 apples + 80 apples + 60 apples = <<40+80+60=180>>180 apples in the three days.
The total number of apples remaining in the tree is 200 apples - 180 apples = <<200-180=20>>20 apples
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