Adam has some blue stickers and red stickers.
If Adam receives another 315 red stickers,
the blue stickers will be 20% as many as the red stickers.
If Adam receives another 90 blue stickers,
the blue stickers will be 80% 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 |
5 u - 315 |
4 p - 90 |
5 p |
Change |
No change |
+ 315 |
+ 90 |
No change |
After |
1 u |
5 u |
4 p |
5 p |
(a)
20% =
20100 =
15 80% =
80100 =
45 Scenario 1 Number of blue stickers at first = 1 u
Number of red stickers at first = 5 u - 315
Scenario 2 Number of blue stickers at first = 4 p - 90
Number of red stickers at first = 5 p
1 u = 4 p - 90 --- (1)
5 u - 315 = 5 p --- (2)
(2)
÷ 51 u - 63 = 1 p
1 u = 1 p + 63 --- (3)
(1) = (3)
4 p - 90 = 1 p + 63
4 p - 1 p = 90 + 63
3 p = 153
1 p = 153 ÷ 3 = 51
Number of blue stickers
= 4 p - 90
= 4 x 51 - 90
= 204 - 90
= 114
(b)
Number of red stickers
= 5 p
= 5 x 51
= 255
Answer(s): (a) 114; (b) 255