Adam has some green stickers and red stickers.
If Adam receives another 500 red stickers,
the green stickers will be 20% as many as the red stickers.
If Adam receives another 89 green stickers,
the green stickers will be 80% as many as the red stickers.
- How many green stickers are there?
- How many red stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Green |
Red |
Green |
Red |
Before |
1 u |
5 u - 500 |
4 p - 89 |
5 p |
Change |
No change |
+ 500 |
+ 89 |
No change |
After |
1 u |
5 u |
4 p |
5 p |
(a)
20% =
20100 =
15 80% =
80100 =
45 Scenario 1 Number of green stickers at first = 1 u
Number of red stickers at first = 5 u - 500
Scenario 2 Number of green stickers at first = 4 p - 89
Number of red stickers at first = 5 p
1 u = 4 p - 89 --- (1)
5 u - 500 = 5 p --- (2)
(2)
÷ 51 u - 100 = 1 p
1 u = 1 p + 100 --- (3)
(1) = (3)
4 p - 89 = 1 p + 100
4 p - 1 p = 89 + 100
3 p = 189
1 p = 189 ÷ 3 = 63
Number of green stickers
= 4 p - 89
= 4 x 63 - 89
= 252 - 89
= 163
(b)
Number of red stickers
= 5 p
= 5 x 63
= 315
Answer(s): (a) 163; (b) 315