Adam has some blue stickers and green stickers.
If 112 blue stickers are added, 30% of the stickers will be green stickers.
If 258 green stickers are added, 25% 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 |
7 u - 112 |
3 u |
1 p |
3 p - 258 |
Change |
+ 112 |
No change |
No change |
+ 258 |
After |
7 u |
3 u |
1 p |
3 p |
(a)
30% =
30100 =
310 25% =
25100 =
14 Scenario 1 Fraction of the stickers that are blue
= 1 -
310 =
710 Number of blue stickers at first = 7 u - 112
Number of green stickers at first = 3 u
Scenario 2 Fraction of the stickers that are green
= 1 -
14=
34 Number of blue stickers at first = 1 p
Number of green stickers at first = 3 p - 258
7 u - 112 = 1 p --- (1)
3 u = 3 p - 258
3 u + 258 = 3 p --- (2)
(1)
x 3 21 u - 336 = 3 p --- (3)
(3) = (2)
21 u - 336 = 3 u + 258
21 u - 3 u = 336 + 258
18 u = 594
1 u = 594 ÷ 18 = 33
Number of blue stickers
= 7 u - 112
= 7 x 33 - 112
= 231 - 112
= 119
(b)
Number of green stickers
= 3 u
= 3 x 33
= 99
Answer(s): (a) 119; (b) 99