Adam has some red stickers and green stickers.
If 279 red stickers are removed, 90% of the stickers will be green stickers.
If 104 red stickers are removed, 20% 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 |
1 u + 279 |
9 u |
36 u + 104 |
9 u |
Change |
- 279 |
No change |
- 104 |
No change |
After |
1x1 = 1 u |
9x1 = 9 u |
4x9 = 36 u |
1x9 = 9 u |
(a)
90% =
90100 =
91020% =
20100 =
15Scenario 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 -
15 =
45 The number of green stickers remains unchanged in both scenarios.
LCM of 9 and 1 = 9
1 u + 279 = 36 u + 104
36 u - 1 u = 279 - 104
35 u = 175
1 u = 175 ÷ 35 = 5
Number of red stickers
= 1 u + 279
= 1 x 5 + 279
= 5 + 279
= 284
(b)
Number of green stickers
= 9 u
= 9 x 5
= 45
Answer(s): (a) 284; (b) 45