Adam has some green stickers and red stickers.
If 120 green stickers are removed, 80% of the stickers will be red stickers.
If 89 green stickers are added, 25% of the stickers will be red stickers.
- How many green stickers are there?
- How many red stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Green |
Red |
Green |
Red |
Before |
1 u + 120 |
4 u |
12 u - 89 |
4 u |
Change |
- 120 |
No change |
+ 89 |
No change |
After |
1x1 = 1 u |
4x1 = 4 u |
3x4 = 12 u |
1x4 = 4 u |
(a)
80% =
80100 =
4525% =
25100 =
14Scenario 1 Fraction of the stickers that are green in the end
= 1 -
45 =
15 Scenario 2
Fraction of the stickers that are green in the end
= 1 -
14 =
34 The number of red stickers remains unchanged in both scenarios.
LCM of 4 and 1 = 4
12 u - 89 = 1 u + 120
12 u - 1 u = 120 + 89
11 u = 209
1 u = 209 ÷ 11 = 19
Number of green stickers
= 1 u + 120
= 1 x 19 + 120
= 19 + 120
= 139
(b)
Number of red stickers
= 4 u
= 4 x 19
= 76
Answer(s): (a) 139; (b) 76