Adam has 140 stickers.
He has 20 less blue stickers than green stickers.
He has 30 less red stickers than blue stickers.
How many less red stickers than green and blue stickers does Adam have?
Choose the smallest group to be 1 u.

Number of red stickers = 1 u
Number of blue stickers = 1 u + 30
Number of green stickers = 1 u + 30 + 20 = 1 u + 50

Total number of stickers
= 1 u + 1 u + 30 + 1 u + 50
= 3 u + 80

3 u + 80 = 140
3 u = 140 - 80
3 u = 60

1 u = 60 ÷ 3 = 20

Total number of green and blue stickers
= 1 u + 30 + 1 u + 50
= 2 u + 80

Number of less red stickers than green and blue stickers
= 2 u + 80 - 1 u
= 2 u - 1 u + 80
= 1 u + 80
= 20 + 80
= 100

Answer(s): 100