Adam has some red stickers and green stickers.
If 275 red stickers are removed, 20% of the stickers will be red stickers.
If 370 green stickers are removed, 10% of the stickers will be green stickers.
- How many red stickers are there?
- How many green stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Red |
Green |
Red |
Green |
Before |
1 u + 275 |
4 u |
9 p |
1 p + 370 |
Change |
- 275 |
No change |
No change |
- 370 |
After |
1 u |
4 u |
9 p |
1 p |
(a)
20% =
20100 =
15 10% =
10100 =
110 Scenario 1Fraction of the stickers that are green
= 1 -
15 =
45 Scenario 2Fraction of the stickers that are red
= 1 -
110 =
9101 u + 275 = 9 p --- (1)
4 u = 1 p + 370 --- (2)
From (1)
1 u = 9 p - 275 --- (3)
(3)
x 44 u = 36 p - 1100 --- (4)
(4) = (2)
36 p - 1100 = 1 p + 370
36 p - 1 p = 1100 + 370
35 p = 1470
1 p = 1470 ÷ 35 = 42Number of red stickers = 9 p
= 9 x 42= 378 (b) Number of green stickers = 1 p + 370 = 42 + 370 = 412 Answer(s): (a) 378; (b) 412