Adam has some green stickers and blue stickers.
If 372 green stickers are removed, 90% of the stickers will be blue stickers.
If 72 green stickers are removed, 40% of the stickers will be blue stickers.
- How many green stickers are there?
- How many blue stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Green |
Blue |
Green |
Blue |
Before |
2 u + 372 |
18 u |
27 u + 72 |
18 u |
Change |
- 372 |
No change |
- 72 |
No change |
After |
1x2 = 2 u |
9x2 = 18 u |
3x9 = 27 u |
2x9 = 18 u |
(a)
90% =
90100 =
91040% =
40100 =
25Scenario 1 Fraction of the stickers that are green in the end
= 1 -
910 =
110 Scenario 2
Fraction of the stickers that are green in the end
= 1 -
25 =
35 The number of blue stickers remains unchanged in both scenarios.
LCM of 9 and 2 = 18
2 u + 372 = 27 u + 72
27 u - 2 u = 372 - 72
25 u = 300
1 u = 300 ÷ 25 = 12
Number of green stickers
= 2 u + 372
= 2 x 12 + 372
= 24 + 372
= 396
(b)
Number of blue stickers
= 18 u
= 18 x 12
= 216
Answer(s): (a) 396; (b) 216