Adam has some blue stickers and red stickers.
If 41 blue stickers are removed, 80% of the stickers will be red stickers.
If 494 red stickers are added, 30% of the stickers will be blue stickers.
- How many blue stickers are there?
- How many red stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Blue |
Red |
Blue |
Red |
Before |
1 u + 41 |
4 u |
3 p |
7 p - 494 |
Change |
- 41 |
No change |
No change |
+ 494 |
After |
1 u |
4 u |
3 p |
7 p |
(a)
80% =
80100
=
45 30% =
30100 =
310 Scenario 1 Fraction of the stickers that are blue in the end
= 1 -
45 =
15 Scenario 2
Fraction of the stickers that are blue in the end
= 1 -
310 =
710 1 u + 41 = 3 p --- (1)
4 u = 7 p - 494 --- (2)
(1)
x 4 4 u + 164 = 4 p
4 u = 4 p - 164 --- (3)
(2) = (3)
7 p - 494 = 4 p - 164
7 p - 4 p = 494 - 164
3 p = 330
1 p = 330 ÷ 3 = 110
Number of blue stickers
= 3 p
= 3 x 110
= 330
(b)
Number of red stickers
= 7 p - 494
= 7 x 110 - 494
= 770 - 494
= 276
Answer(s): (a) 330; (b) 276