Adam has some green stickers and red stickers.
If 338 green stickers are removed, 90% of the stickers will be red stickers.
If 130 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 + 338 |
9 u |
27 u - 130 |
9 u |
Change |
- 338 |
No change |
+ 130 |
No change |
After |
1x1 = 1 u |
9x1 = 9 u |
3x9 = 27 u |
1x9 = 9 u |
(a)
90% =
90100 =
91025% =
25100 =
14Scenario 1 Fraction of the stickers that are green in the end
= 1 -
910 =
110 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 9 and 1 = 9
27 u - 130 = 1 u + 338
27 u - 1 u = 338 + 130
26 u = 468
1 u = 468 ÷ 26 = 18
Number of green stickers
= 1 u + 338
= 1 x 18 + 338
= 18 + 338
= 356
(b)
Number of red stickers
= 9 u
= 9 x 18
= 162
Answer(s): (a) 356; (b) 162