Adam has some green stickers and red stickers.
If Adam gives away 15 green stickers,
the green stickers will be 10% as many as the red stickers.
If Adam gives away 90 red stickers,
the green stickers will be 40% 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 + 15 |
10 u |
2 p |
5 p + 90 |
Change |
- 15 |
No change |
No change |
- 90 |
After |
1 u |
10 u |
2 p |
5 p |
(a)
10% =
10100 =
110 40% =
40100 =
25 Scenario 1 Number of green stickers at first = 1 u + 15
Number of red stickers at first = 10 u
Scenario 2 Number of green stickers at first = 2 p
Number of red stickers at first = 5 p + 90
1 u + 15 = 2 p --- (1)
10 u = 5 p + 90 --- (2)
(1)
x 10 10 u + 150 = 20 p
10 u = 20 p - 150 --- (3)
(3) = (2)
20 p - 150 = 5 p + 90
20 p - 5 p = 150 + 90
15 p = 240
1 p = 240 ÷ 15 = 16
Number of green stickers
= 2 p
= 2 x 16
= 32
(b)
Number of red stickers at first
= 5 p + 90
= 5 x 16 + 90
= 80 + 90
= 170
Answer(s): (a) 32; (b) 170