Adam has some red stickers and green stickers.
If 399 red stickers are removed, 25% of the stickers will be red stickers.
If 299 green 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 + 399 |
3 u |
4 p |
1 p + 299 |
Change |
- 399 |
No change |
No change |
- 299 |
After |
1 u |
3 u |
4 p |
1 p |
(a)
25% =
25100 =
14 20% =
20100 =
15 Scenario 1Fraction of the stickers that are green
= 1 -
14 =
34 Scenario 2Fraction of the stickers that are red
= 1 -
15 =
451 u + 399 = 4 p --- (1)
3 u = 1 p + 299 --- (2)
From (1)
1 u = 4 p - 399 --- (3)
(3)
x 33 u = 12 p - 1197 --- (4)
(4) = (2)
12 p - 1197 = 1 p + 299
12 p - 1 p = 1197 + 299
11 p = 1496
1 p = 1496 ÷ 11 = 136Number of red stickers = 4 p
= 4 x 136= 544 (b) Number of green stickers = 1 p + 299 = 136 + 299 = 435 Answer(s): (a) 544; (b) 435