Adam has some blue stickers and green stickers.
If 305 blue stickers are added, 40% of the stickers will be green stickers.
If 120 green stickers are added, 20% of the stickers will be blue stickers.
- How many blue stickers are there?
- How many green stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Blue |
Green |
Blue |
Green |
Before |
3 u - 305 |
2 u |
1 p |
4 p - 120 |
Change |
+ 305 |
No change |
No change |
+ 120 |
After |
3 u |
2 u |
1 p |
4 p |
(a)
40% =
40100 =
25 20% =
20100 =
15 Scenario 1 Fraction of the stickers that are blue
= 1 -
25 =
35 Number of blue stickers at first = 3 u - 305
Number of green stickers at first = 2 u
Scenario 2 Fraction of the stickers that are green
= 1 -
15=
45 Number of blue stickers at first = 1 p
Number of green stickers at first = 4 p - 120
3 u - 305 = 1 p --- (1)
2 u = 4 p - 120
2 u + 120 = 4 p --- (2)
(1)
x 4 12 u - 1220 = 4 p --- (3)
(3) = (2)
12 u - 1220 = 2 u + 120
12 u - 2 u = 1220 + 120
10 u = 1340
1 u = 1340 ÷ 10 = 134
Number of blue stickers
= 3 u - 305
= 3 x 134 - 305
= 402 - 305
= 97
(b)
Number of green stickers
= 2 u
= 2 x 134
= 268
Answer(s): (a) 97; (b) 268