Adam has some blue stickers and green stickers.
If 101 blue stickers are added, 30% of the stickers will be green stickers.
If 396 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 |
7 u - 101 |
3 u |
1 p |
4 p - 396 |
Change |
+ 101 |
No change |
No change |
+ 396 |
After |
7 u |
3 u |
1 p |
4 p |
(a)
30% =
30100 =
310 20% =
20100 =
15 Scenario 1 Fraction of the stickers that are blue
= 1 -
310 =
710 Number of blue stickers at first = 7 u - 101
Number of green stickers at first = 3 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 - 396
7 u - 101 = 1 p --- (1)
3 u = 4 p - 396
3 u + 396 = 4 p --- (2)
(1)
x 4 28 u - 404 = 4 p --- (3)
(3) = (2)
28 u - 404 = 3 u + 396
28 u - 3 u = 404 + 396
25 u = 800
1 u = 800 ÷ 25 = 32
Number of blue stickers
= 7 u - 101
= 7 x 32 - 101
= 224 - 101
= 123
(b)
Number of green stickers
= 3 u
= 3 x 32
= 96
Answer(s): (a) 123; (b) 96