Adam has some red stickers and blue stickers.
If 11 red stickers are removed, 80% of the stickers will be blue stickers.
If 599 blue stickers are added, 10% of the stickers will be red stickers.
- How many red stickers are there?
- How many blue stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Red |
Blue |
Red |
Blue |
Before |
1 u + 11 |
4 u |
1 p |
9 p - 599 |
Change |
- 11 |
No change |
No change |
+ 599 |
After |
1 u |
4 u |
1 p |
9 p |
(a)
80% =
80100
=
45 10% =
10100 =
110 Scenario 1 Fraction of the stickers that are red in the end
= 1 -
45 =
15 Scenario 2
Fraction of the stickers that are red in the end
= 1 -
110 =
910 1 u + 11 = 1 p --- (1)
4 u = 9 p - 599 --- (2)
(1)
x 4 4 u + 44 = 4 p
4 u = 4 p - 44 --- (3)
(2) = (3)
9 p - 599 = 4 p - 44
9 p - 4 p = 599 - 44
5 p = 555
1 p = 555 ÷ 5 = 111
Number of red stickers
= 1 p
= 1 x 111
= 111
(b)
Number of blue stickers
= 9 p - 599
= 9 x 111 - 599
= 999 - 599
= 400
Answer(s): (a) 111; (b) 400