Adam has some red stickers and blue stickers.
If Adam gives away 15 red stickers,
the red stickers will be 20% as many as the blue stickers.
If Adam gives away 10 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 + 15 |
5 u |
2 p |
5 p + 10 |
Change |
- 15 |
No change |
No change |
- 10 |
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 + 15
Number of blue stickers at first = 5 u
Scenario 2 Number of red stickers at first = 2 p
Number of blue stickers at first = 5 p + 10
1 u + 15 = 2 p --- (1)
5 u = 5 p + 10 --- (2)
(1)
x 5 5 u + 75 = 10 p
5 u = 10 p - 75 --- (3)
(3) = (2)
10 p - 75 = 5 p + 10
10 p - 5 p = 75 + 10
5 p = 85
1 p = 85 ÷ 5 = 17
Number of red stickers
= 2 p
= 2 x 17
= 34
(b)
Number of blue stickers at first
= 5 p + 10
= 5 x 17 + 10
= 85 + 10
= 95
Answer(s): (a) 34; (b) 95