Adam has 191 stickers.
After
79 of the blue stickers is given away and
another 40 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 |
2 u - 40 |
Change |
- 7 u |
+ 40 |
After |
2 u |
2 u |
(a)
Fraction of the blue stickers left
= 1 -
79 =
29 The number of blue stickers and green stickers in the end is the same.
Total number of stickers at first
= 9 u + 2 u - 40
= 11 u - 40
11 u - 40 = 191
11 u = 191 + 40
11 u = 231
1 u = 231 ÷ 11 = 21
Number of blue stickers in the end
= 2 u
= 2 x 21
= 42
(b)
Number of less green stickers than blue stickers at first
= 9 u - (2 u - 40)
= 9 u - 2 u + 40
= 7 u + 40
= 7 x 21 + 40
= 147 + 40
= 187
(c)
Number of blue stickers given away
= 7 u
= 7 x 21
= 147
Answer(s): (a) 42; (b) 187; (c) 147