Adam has some red stickers and blue stickers.
If 120 red stickers are removed, 25% of the stickers will be red stickers.
If 368 blue stickers are removed, 10% 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 + 120 |
3 u |
9 p |
1 p + 368 |
Change |
- 120 |
No change |
No change |
- 368 |
After |
1 u |
3 u |
9 p |
1 p |
(a)
25% =
25100 =
14 10% =
10100 =
110 Scenario 1Fraction of the stickers that are blue
= 1 -
14 =
34 Scenario 2Fraction of the stickers that are red
= 1 -
110 =
9101 u + 120 = 9 p --- (1)
3 u = 1 p + 368 --- (2)
From (1)
1 u = 9 p - 120 --- (3)
(3)
x 33 u = 27 p - 360 --- (4)
(4) = (2)
27 p - 360 = 1 p + 368
27 p - 1 p = 360 + 368
26 p = 728
1 p = 728 ÷ 26 = 28Number of red stickers = 9 p
= 9 x 28= 252 (b) Number of blue stickers = 1 p + 368 = 28 + 368 = 396 Answer(s): (a) 252; (b) 396