Adam has some green stickers and red stickers.
If 33 green stickers are removed, 75% of the stickers will be red stickers.
If 531 red stickers are added, 10% of the stickers will be green stickers.
- How many green stickers are there?
- How many red stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Green |
Red |
Green |
Red |
Before |
1 u + 33 |
3 u |
1 p |
9 p - 531 |
Change |
- 33 |
No change |
No change |
+ 531 |
After |
1 u |
3 u |
1 p |
9 p |
(a)
75% =
75100
=
34 10% =
10100 =
110 Scenario 1 Fraction of the stickers that are green in the end
= 1 -
34 =
14 Scenario 2
Fraction of the stickers that are green in the end
= 1 -
110 =
910 1 u + 33 = 1 p --- (1)
3 u = 9 p - 531 --- (2)
(1)
x 3 3 u + 99 = 3 p
3 u = 3 p - 99 --- (3)
(2) = (3)
9 p - 531 = 3 p - 99
9 p - 3 p = 531 - 99
6 p = 432
1 p = 432 ÷ 6 = 72
Number of green stickers
= 1 p
= 1 x 72
= 72
(b)
Number of red stickers
= 9 p - 531
= 9 x 72 - 531
= 648 - 531
= 117
Answer(s): (a) 72; (b) 117