Adam has some blue stickers and red stickers.
If Adam receives another 615 red stickers,
the blue stickers will be 20% as many as the red stickers.
If Adam receives another 18 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 - 615 |
4 p - 18 |
5 p |
Change |
No change |
+ 615 |
+ 18 |
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 - 615
Scenario 2 Number of blue stickers at first = 4 p - 18
Number of red stickers at first = 5 p
1 u = 4 p - 18 --- (1)
5 u - 615 = 5 p --- (2)
(2)
÷ 51 u - 123 = 1 p
1 u = 1 p + 123 --- (3)
(1) = (3)
4 p - 18 = 1 p + 123
4 p - 1 p = 18 + 123
3 p = 141
1 p = 141 ÷ 3 = 47
Number of blue stickers
= 4 p - 18
= 4 x 47 - 18
= 188 - 18
= 170
(b)
Number of red stickers
= 5 p
= 5 x 47
= 235
Answer(s): (a) 170; (b) 235