Adam has some red stickers and blue stickers.
If 400 red stickers are removed, 25% of the stickers will be red stickers.
If 351 blue stickers are removed, 20% of the stickers will be blue stickers.
- How many red stickers are there?
- How many blue stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Red |
Blue |
Red |
Blue |
Before |
1 u + 400 |
3 u |
4 p |
1 p + 351 |
Change |
- 400 |
No change |
No change |
- 351 |
After |
1 u |
3 u |
4 p |
1 p |
(a)
25% =
25100 =
14 20% =
20100 =
15 Scenario 1Fraction of the stickers that are blue
= 1 -
14 =
34 Scenario 2Fraction of the stickers that are red
= 1 -
15 =
451 u + 400 = 4 p --- (1)
3 u = 1 p + 351 --- (2)
From (1)
1 u = 4 p - 400 --- (3)
(3)
x 33 u = 12 p - 1200 --- (4)
(4) = (2)
12 p - 1200 = 1 p + 351
12 p - 1 p = 1200 + 351
11 p = 1551
1 p = 1551 ÷ 11 = 141Number of red stickers = 4 p
= 4 x 141= 564 (b) Number of blue stickers = 1 p + 351 = 141 + 351 = 492 Answer(s): (a) 564; (b) 492