Adam has some green stickers and red stickers.
If Adam receives another 380 red stickers,
the green stickers will be 20% as many as the red stickers.
If Adam receives another 20 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 - 380 |
4 p - 20 |
5 p |
Change |
No change |
+ 380 |
+ 20 |
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 - 380
Scenario 2 Number of green stickers at first = 4 p - 20
Number of red stickers at first = 5 p
1 u = 4 p - 20 --- (1)
5 u - 380 = 5 p --- (2)
(2)
÷ 51 u - 76 = 1 p
1 u = 1 p + 76 --- (3)
(1) = (3)
4 p - 20 = 1 p + 76
4 p - 1 p = 20 + 76
3 p = 96
1 p = 96 ÷ 3 = 32
Number of green stickers
= 4 p - 20
= 4 x 32 - 20
= 128 - 20
= 108
(b)
Number of red stickers
= 5 p
= 5 x 32
= 160
Answer(s): (a) 108; (b) 160