Adam has 180 stickers.
He has 30 less blue stickers than green stickers.
He has 60 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 + 60
Number of green stickers = 1 u + 60 + 30 = 1 u + 90

Total number of stickers
= 1 u + 1 u + 60 + 1 u + 90
= 3 u + 150

3 u + 150 = 180
3 u = 180 - 150
3 u = 30

1 u = 30 ÷ 3 = 10

Total number of green and blue stickers
= 1 u + 60 + 1 u + 90
= 2 u + 150

Number of less red stickers than green and blue stickers
= 2 u + 150 - 1 u
= 2 u - 1 u + 150
= 1 u + 150
= 10 + 150
= 160

Answer(s): 160