21 picks
altogether (2x+5x)=21
7x=21
x=3
2*3=6 orange picks
or
x=orange, y = greens
x+y=21
x/y=2/5,----> y=5x/2
x+5x/2=21
2x/2+5x/2=21
7x/2=21
7x=42,
x=6 orange picks
Answer:
I don't know how to do this thing
The answer would be 6 9/35 which would round to 6.5