Adam has some red stickers and blue stickers.
If Adam gives away 10 red stickers,
the red stickers will be 10% as many as the blue stickers.
If Adam gives away 200 blue stickers,
the red stickers will be 40% as many as the blue stickers.
- How many red stickers are there?
- How many blue stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Red |
Blue |
Red |
Blue |
Before |
1 u + 10 |
10 u |
2 p |
5 p + 200 |
Change |
- 10 |
No change |
No change |
- 200 |
After |
1 u |
10 u |
2 p |
5 p |
(a)
10% =
10100 =
110 40% =
40100 =
25 Scenario 1 Number of red stickers at first = 1 u + 10
Number of blue stickers at first = 10 u
Scenario 2 Number of red stickers at first = 2 p
Number of blue stickers at first = 5 p + 200
1 u + 10 = 2 p --- (1)
10 u = 5 p + 200 --- (2)
(1)
x 10 10 u + 100 = 20 p
10 u = 20 p - 100 --- (3)
(3) = (2)
20 p - 100 = 5 p + 200
20 p - 5 p = 100 + 200
15 p = 300
1 p = 300 ÷ 15 = 20
Number of red stickers
= 2 p
= 2 x 20
= 40
(b)
Number of blue stickers at first
= 5 p + 200
= 5 x 20 + 200
= 100 + 200
= 300
Answer(s): (a) 40; (b) 300