Adam has some blue stickers and green stickers.
If 276 blue stickers are added, 30% of the stickers will be green stickers.
If 171 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 - 276 |
3 u |
1 p |
4 p - 171 |
Change |
+ 276 |
No change |
No change |
+ 171 |
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 - 276
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 - 171
7 u - 276 = 1 p --- (1)
3 u = 4 p - 171
3 u + 171 = 4 p --- (2)
(1)
x 4 28 u - 1104 = 4 p --- (3)
(3) = (2)
28 u - 1104 = 3 u + 171
28 u - 3 u = 1104 + 171
25 u = 1275
1 u = 1275 ÷ 25 = 51
Number of blue stickers
= 7 u - 276
= 7 x 51 - 276
= 357 - 276
= 81
(b)
Number of green stickers
= 3 u
= 3 x 51
= 153
Answer(s): (a) 81; (b) 153