Adam has some blue stickers and green stickers.
If 380 blue stickers are removed, 80% of the stickers will be green stickers.
If 120 blue stickers are added, 30% of the stickers will be green stickers.
- How many blue stickers are there?
- How many green stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Blue |
Green |
Blue |
Green |
Before |
3 u + 380 |
12 u |
28 u - 120 |
12 u |
Change |
- 380 |
No change |
+ 120 |
No change |
After |
1x3 = 3 u |
4x3 = 12 u |
7x4 = 28 u |
3x4 = 12 u |
(a)
80% =
80100 =
4530% =
30100 =
310Scenario 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 The number of green stickers remains unchanged in both scenarios.
LCM of 4 and 3 = 12
28 u - 120 = 3 u + 380
28 u - 3 u = 380 + 120
25 u = 500
1 u = 500 ÷ 25 = 20
Number of blue stickers
= 3 u + 380
= 3 x 20 + 380
= 60 + 380
= 440
(b)
Number of green stickers
= 12 u
= 12 x 20
= 240
Answer(s): (a) 440; (b) 240