Adam has some blue stickers and green stickers.
If 313 blue stickers are added, 40% of the stickers will be green stickers.
If 308 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 - 313 |
2 u |
1 p |
4 p - 308 |
Change |
+ 313 |
No change |
No change |
+ 308 |
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 - 313
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 - 308
3 u - 313 = 1 p --- (1)
2 u = 4 p - 308
2 u + 308 = 4 p --- (2)
(1)
x 4 12 u - 1252 = 4 p --- (3)
(3) = (2)
12 u - 1252 = 2 u + 308
12 u - 2 u = 1252 + 308
10 u = 1560
1 u = 1560 ÷ 10 = 156
Number of blue stickers
= 3 u - 313
= 3 x 156 - 313
= 468 - 313
= 155
(b)
Number of green stickers
= 2 u
= 2 x 156
= 312
Answer(s): (a) 155; (b) 312