Adam has some blue stickers and red stickers.
If Adam gives away 15 blue stickers,
the blue stickers will be 10% as many as the red stickers.
If Adam gives away 30 red stickers,
the blue stickers will be 40% as many as the red stickers.
- How many blue stickers are there?
- How many red stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Blue |
Red |
Blue |
Red |
Before |
1 u + 15 |
10 u |
2 p |
5 p + 30 |
Change |
- 15 |
No change |
No change |
- 30 |
After |
1 u |
10 u |
2 p |
5 p |
(a)
10% =
10100 =
110 40% =
40100 =
25 Scenario 1 Number of blue stickers at first = 1 u + 15
Number of red stickers at first = 10 u
Scenario 2 Number of blue stickers at first = 2 p
Number of red stickers at first = 5 p + 30
1 u + 15 = 2 p --- (1)
10 u = 5 p + 30 --- (2)
(1)
x 10 10 u + 150 = 20 p
10 u = 20 p - 150 --- (3)
(3) = (2)
20 p - 150 = 5 p + 30
20 p - 5 p = 150 + 30
15 p = 180
1 p = 180 ÷ 15 = 12
Number of blue stickers
= 2 p
= 2 x 12
= 24
(b)
Number of red stickers at first
= 5 p + 30
= 5 x 12 + 30
= 60 + 30
= 90
Answer(s): (a) 24; (b) 90