Adam has some red stickers and green stickers.
If Adam gives away 18 red stickers,
the red stickers will be 20% as many as the green stickers.
If Adam gives away 40 green stickers,
the red stickers will be 40% as many as the green stickers.
- How many red stickers are there?
- How many green stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Red |
Green |
Red |
Green |
Before |
1 u + 18 |
5 u |
2 p |
5 p + 40 |
Change |
- 18 |
No change |
No change |
- 40 |
After |
1 u |
5 u |
2 p |
5 p |
(a)
20% =
20100 =
15 40% =
40100 =
25 Scenario 1 Number of red stickers at first = 1 u + 18
Number of green stickers at first = 5 u
Scenario 2 Number of red stickers at first = 2 p
Number of green stickers at first = 5 p + 40
1 u + 18 = 2 p --- (1)
5 u = 5 p + 40 --- (2)
(1)
x 5 5 u + 90 = 10 p
5 u = 10 p - 90 --- (3)
(3) = (2)
10 p - 90 = 5 p + 40
10 p - 5 p = 90 + 40
5 p = 130
1 p = 130 ÷ 5 = 26
Number of red stickers
= 2 p
= 2 x 26
= 52
(b)
Number of green stickers at first
= 5 p + 40
= 5 x 26 + 40
= 130 + 40
= 170
Answer(s): (a) 52; (b) 170