Beth has 72/3 = <<72/3=24>>24 marbles of each color
Beth has 24-5 = <<24-5=19>>19 red ones left.
Beth lost 5*2 = <<5*2=10>>10 blue ones.
Beth has 24-10 = <<24-10=14>>14 blue ones left.
Beth lost 5*3 = <<5*3=15>>15 yellow ones.
Beth has 24-15 = <<24-15=9>>9 yellow ones left.
She has a total of 19+14+9 = <<19+14+9=42>>42 marbles left.
#### 42