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 green stickers than blue stickers.
He has 100 less red stickers than
the sum of the number of green and blue stickers.
- How many more red stickers than blue stickers are there?
- How many less green stickers than red stickers are there?
- How many blue and red stickers are there?
(a)
Choose the smallest group to be 1 u.
Number of green stickers = 1 u
Number of blue stickers = 1 u + 20
Number of blue and green stickers
= 1 u + 1 u + 20
= 2 u + 20
Number of red stickers
= 2 u + 20 - 100
= 2 u - 80
Number of more red stickers than blue stickers
= (2 u - 80) - (1 u + 20)
= 2 u - 80 - 1 u - 20
= 2 u - 1 u - 80 - 20
= 1 u - 100
(b)
Number of less green stickers than red stickers
= (2 u - 80) - 1 u
= 2 u - 80 - 1 u
= 2 u - 1 u - 80
= 1 u - 80
(c)
Number of blue and red stickers
= (1 u + 20) + (2 u - 80)
= 1 u + 2 u + 20 - 80
= 3 u - 60
Answer(s): (a) 1 u - 100; (b) 1 u - 80; (c) 3 u - 60