Adam has 180 stickers.
After
29 of the blue stickers is given away and
another 12 green stickers are bought,
there is an equal number of blue and green stickers.
- How many blue stickers are there in the end?
- How many less green stickers than blue stickers are there at first?
- How many blue stickers are given away?
|
Blue |
Green |
Before |
9 u |
7 u - 12 |
Change |
- 2 u |
+ 12 |
After |
7 u |
7 u |
(a)
Fraction of the blue stickers left
= 1 -
29 =
79 The number of blue stickers and green stickers in the end is the same.
Total number of stickers at first
= 9 u + 7 u - 12
= 16 u - 12
16 u - 12 = 180
16 u = 180 + 12
16 u = 192
1 u = 192 ÷ 16 = 12
Number of blue stickers in the end
= 7 u
= 7 x 12
= 84
(b)
Number of less green stickers than blue stickers at first
= 9 u - (7 u - 12)
= 9 u - 7 u + 12
= 2 u + 12
= 2 x 12 + 12
= 24 + 12
= 36
(c)
Number of blue stickers given away
= 2 u
= 2 x 12
= 24
Answer(s): (a) 84; (b) 36; (c) 24