Adam has some blue stickers and green stickers.
If 72 blue stickers are removed, 80% of the stickers will be green stickers.
If 519 green stickers are added, 30% of the stickers will be blue stickers.
- How many blue stickers are there?
- How many green stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Blue |
Green |
Blue |
Green |
Before |
1 u + 72 |
4 u |
3 p |
7 p - 519 |
Change |
- 72 |
No change |
No change |
+ 519 |
After |
1 u |
4 u |
3 p |
7 p |
(a)
80% =
80100
=
45 30% =
30100 =
310 Scenario 1 Fraction of the stickers that are blue in the end
= 1 -
45 =
15 Scenario 2
Fraction of the stickers that are blue in the end
= 1 -
310 =
710 1 u + 72 = 3 p --- (1)
4 u = 7 p - 519 --- (2)
(1)
x 4 4 u + 288 = 4 p
4 u = 4 p - 288 --- (3)
(2) = (3)
7 p - 519 = 4 p - 288
7 p - 4 p = 519 - 288
3 p = 231
1 p = 231 ÷ 3 = 77
Number of blue stickers
= 3 p
= 3 x 77
= 231
(b)
Number of green stickers
= 7 p - 519
= 7 x 77 - 519
= 539 - 519
= 20
Answer(s): (a) 231; (b) 20