Adam has some red stickers and green stickers.
If 263 red stickers are removed, 90% of the stickers will be green stickers.
If 112 red stickers are added, 40% of the stickers will be green stickers.
- How many red stickers are there?
- How many green stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Red |
Green |
Red |
Green |
Before |
2 u + 263 |
18 u |
27 u - 112 |
18 u |
Change |
- 263 |
No change |
+ 112 |
No change |
After |
1x2 = 2 u |
9x2 = 18 u |
3x9 = 27 u |
2x9 = 18 u |
(a)
90% =
90100 =
91040% =
40100 =
25Scenario 1 Fraction of the stickers that are red in the end
= 1 -
910 =
110 Scenario 2
Fraction of the stickers that are red in the end
= 1 -
25 =
35 The number of green stickers remains unchanged in both scenarios.
LCM of 9 and 2 = 18
27 u - 112 = 2 u + 263
27 u - 2 u = 263 + 112
25 u = 375
1 u = 375 ÷ 25 = 15
Number of red stickers
= 2 u + 263
= 2 x 15 + 263
= 30 + 263
= 293
(b)
Number of green stickers
= 18 u
= 18 x 15
= 270
Answer(s): (a) 293; (b) 270