Adam has some blue stickers and red stickers.
If 19 blue stickers are removed, 75% of the stickers will be red stickers.
If 409 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 + 19 |
3 u |
3 p |
7 p - 409 |
Change |
- 19 |
No change |
No change |
+ 409 |
After |
1 u |
3 u |
3 p |
7 p |
(a)
75% =
75100
=
34 30% =
30100 =
310 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 -
310 =
710 1 u + 19 = 3 p --- (1)
3 u = 7 p - 409 --- (2)
(1)
x 3 3 u + 57 = 3 p
3 u = 3 p - 57 --- (3)
(2) = (3)
7 p - 409 = 3 p - 57
7 p - 3 p = 409 - 57
4 p = 352
1 p = 352 ÷ 4 = 88
Number of blue stickers
= 3 p
= 3 x 88
= 264
(b)
Number of red stickers
= 7 p - 409
= 7 x 88 - 409
= 616 - 409
= 207
Answer(s): (a) 264; (b) 207