Adam has some red stickers and blue stickers.
If Adam receives another 640 blue stickers,
the red stickers will be 20% as many as the blue stickers.
If Adam receives another 43 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 - 640 |
4 p - 43 |
5 p |
Change |
No change |
+ 640 |
+ 43 |
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 - 640
Scenario 2 Number of red stickers at first = 4 p - 43
Number of blue stickers at first = 5 p
1 u = 4 p - 43 --- (1)
5 u - 640 = 5 p --- (2)
(2)
÷ 51 u - 128 = 1 p
1 u = 1 p + 128 --- (3)
(1) = (3)
4 p - 43 = 1 p + 128
4 p - 1 p = 43 + 128
3 p = 171
1 p = 171 ÷ 3 = 57
Number of red stickers
= 4 p - 43
= 4 x 57 - 43
= 228 - 43
= 185
(b)
Number of blue stickers
= 5 p
= 5 x 57
= 285
Answer(s): (a) 185; (b) 285