Adam has some blue stickers and red stickers.
If 42 blue stickers are removed, 75% of the stickers will be red stickers.
If 522 red stickers are added, 10% 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 + 42 |
3 u |
1 p |
9 p - 522 |
Change |
- 42 |
No change |
No change |
+ 522 |
After |
1 u |
3 u |
1 p |
9 p |
(a)
75% =
75100
=
34 10% =
10100 =
110 Scenario 1 Fraction of the stickers that are blue in the end
= 1 -
34 =
14 Scenario 2
Fraction of the stickers that are blue in the end
= 1 -
110 =
910 1 u + 42 = 1 p --- (1)
3 u = 9 p - 522 --- (2)
(1)
x 3 3 u + 126 = 3 p
3 u = 3 p - 126 --- (3)
(2) = (3)
9 p - 522 = 3 p - 126
9 p - 3 p = 522 - 126
6 p = 396
1 p = 396 ÷ 6 = 66
Number of blue stickers
= 1 p
= 1 x 66
= 66
(b)
Number of red stickers
= 9 p - 522
= 9 x 66 - 522
= 594 - 522
= 72
Answer(s): (a) 66; (b) 72