Fill in the blanks.
For (a) to (c), give the answers in units (Eg 1 u) or unit equations (Eg 1 u + 2).
Adam has some stickers.
He has 20 less blue stickers than green stickers.
He has 90 less red stickers than
the sum of the number of blue and green stickers.
- How many more red stickers than green stickers are there?
- How many less blue stickers than red stickers are there?
- How many green and red stickers are there?
(a)
Choose the smallest group to be 1 u.
Number of blue stickers = 1 u
Number of green stickers = 1 u + 20
Number of green and blue stickers
= 1 u + 1 u + 20
= 2 u + 20
Number of red stickers
= 2 u + 20 - 90
= 2 u - 70
Number of more red stickers than green stickers
= (2 u - 70) - (1 u + 20)
= 2 u - 70 - 1 u - 20
= 2 u - 1 u - 70 - 20
= 1 u - 90
(b)
Number of less blue stickers than red stickers
= (2 u - 70) - 1 u
= 2 u - 70 - 1 u
= 2 u - 1 u - 70
= 1 u - 70
(c)
Number of green and red stickers
= (1 u + 20) + (2 u - 70)
= 1 u + 2 u + 20 - 70
= 3 u - 50
Answer(s): (a) 1 u - 90; (b) 1 u - 70; (c) 3 u - 50