Adam has some blue stickers and red stickers.
If Adam receives another 20 blue stickers,
the blue stickers will be 25% as many as the red stickers.
If Adam gives away 448 red stickers,
the blue stickers will be 75% as many as the red stickers.
- How many blue stickers are there?
- How many red stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Green |
Blue |
Green |
Blue |
Before |
1 u - 20 |
4 u |
3 p |
4 p + 448 |
Change |
+ 20 |
No change |
No change |
- 448 |
After |
1 u |
4 u |
3 p |
4 p |
(a)
25% =
25100 =
14 75% =
75100 =
34 Scenario 1 Number of green stickers at first = 1 u - 20
Number of blue stickers at first = 4 u
Scenario 2 Number of green stickers at first = 3 p
Number of blue stickers at first = 4 p + 448
1 u - 20 = 3 p --- (1)
4 u = 4 p + 448 --- (2)
From (1)1 u = 20 + 3 p --- (3) (3) x 44 u = 80 + 12 p --- (4)
(4) = (2)80 + 12 p = 4 p + 448 12 p - 4 p = 448 - 808 p = 368
1 p = 368 ÷ 8 = 46
Number of blue stickers = 3 p = 3 x 46 = 138 (b) Number of red stickers = 4 p + 448 = 4 x 46 + 448
= 184 + 448= 632 Answer(s): (a) 138; (b) 632