Adam has 131 stickers.
After
57 of the blue stickers is given away and
another 13 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 |
7 u |
2 u - 13 |
Change |
- 5 u |
+ 13 |
After |
2 u |
2 u |
(a)
Fraction of the blue stickers left
= 1 -
57 =
27 The number of blue stickers and green stickers in the end is the same.
Total number of stickers at first
= 7 u + 2 u - 13
= 9 u - 13
9 u - 13 = 131
9 u = 131 + 13
9 u = 144
1 u = 144 ÷ 9 = 16
Number of blue stickers in the end
= 2 u
= 2 x 16
= 32
(b)
Number of less green stickers than blue stickers at first
= 7 u - (2 u - 13)
= 7 u - 2 u + 13
= 5 u + 13
= 5 x 16 + 13
= 80 + 13
= 93
(c)
Number of blue stickers given away
= 5 u
= 5 x 16
= 80
Answer(s): (a) 32; (b) 93; (c) 80