Adam has some blue stickers and green stickers.
If 372 blue stickers are added, 40% of the stickers will be green stickers.
If 372 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 - 372 |
2 u |
1 p |
4 p - 372 |
Change |
+ 372 |
No change |
No change |
+ 372 |
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 - 372
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 - 372
3 u - 372 = 1 p --- (1)
2 u = 4 p - 372
2 u + 372 = 4 p --- (2)
(1)
x 4 12 u - 1488 = 4 p --- (3)
(3) = (2)
12 u - 1488 = 2 u + 372
12 u - 2 u = 1488 + 372
10 u = 1860
1 u = 1860 ÷ 10 = 186
Number of blue stickers
= 3 u - 372
= 3 x 186 - 372
= 558 - 372
= 186
(b)
Number of green stickers
= 2 u
= 2 x 186
= 372
Answer(s): (a) 186; (b) 372