Adam has some red stickers and blue stickers.
If Adam gives away 45 red stickers,
the red stickers will be 10% as many as the blue stickers.
If Adam gives away 390 blue stickers,
the red stickers will be 80% 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 + 45 |
10 u |
4 p |
5 p + 390 |
Change |
- 45 |
No change |
No change |
- 390 |
After |
1 u |
10 u |
4 p |
5 p |
(a)
10% =
10100 =
110 80% =
80100 =
45 Scenario 1 Number of red stickers at first = 1 u + 45
Number of blue stickers at first = 10 u
Scenario 2 Number of red stickers at first = 4 p
Number of blue stickers at first = 5 p + 390
1 u + 45 = 4 p --- (1)
10 u = 5 p + 390 --- (2)
(1)
x 10 10 u + 450 = 40 p
10 u = 40 p - 450 --- (3)
(3) = (2)
40 p - 450 = 5 p + 390
40 p - 5 p = 450 + 390
35 p = 840
1 p = 840 ÷ 35 = 24
Number of red stickers
= 4 p
= 4 x 24
= 96
(b)
Number of blue stickers at first
= 5 p + 390
= 5 x 24 + 390
= 120 + 390
= 510
Answer(s): (a) 96; (b) 510