Adam has some red stickers and blue stickers.
If Adam receives another 900 blue stickers,
the red stickers will be 20% as many as the blue stickers.
If Adam receives another 78 red 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 |
5 u - 900 |
4 p - 78 |
5 p |
Change |
No change |
+ 900 |
+ 78 |
No change |
After |
1 u |
5 u |
4 p |
5 p |
(a)
20% =
20100 =
15 80% =
80100 =
45 Scenario 1 Number of red stickers at first = 1 u
Number of blue stickers at first = 5 u - 900
Scenario 2 Number of red stickers at first = 4 p - 78
Number of blue stickers at first = 5 p
1 u = 4 p - 78 --- (1)
5 u - 900 = 5 p --- (2)
(2)
÷ 51 u - 180 = 1 p
1 u = 1 p + 180 --- (3)
(1) = (3)
4 p - 78 = 1 p + 180
4 p - 1 p = 78 + 180
3 p = 258
1 p = 258 ÷ 3 = 86
Number of red stickers
= 4 p - 78
= 4 x 86 - 78
= 344 - 78
= 266
(b)
Number of blue stickers
= 5 p
= 5 x 86
= 430
Answer(s): (a) 266; (b) 430