Adam has some red stickers and green stickers.
If Adam receives another 850 green stickers,
the red stickers will be 20% as many as the green stickers.
If Adam receives another 13 red stickers,
the red stickers will be 80% as many as the 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 |
5 u - 850 |
4 p - 13 |
5 p |
Change |
No change |
+ 850 |
+ 13 |
No change |
After |
1 u |
5 u |
4 p |
5 p |
(a)
20% =
20100 =
15 80% =
80100 =
45 Scenario 1 Number of red stickers at first = 1 u
Number of green stickers at first = 5 u - 850
Scenario 2 Number of red stickers at first = 4 p - 13
Number of green stickers at first = 5 p
1 u = 4 p - 13 --- (1)
5 u - 850 = 5 p --- (2)
(2)
÷ 51 u - 170 = 1 p
1 u = 1 p + 170 --- (3)
(1) = (3)
4 p - 13 = 1 p + 170
4 p - 1 p = 13 + 170
3 p = 183
1 p = 183 ÷ 3 = 61
Number of red stickers
= 4 p - 13
= 4 x 61 - 13
= 244 - 13
= 231
(b)
Number of green stickers
= 5 p
= 5 x 61
= 305
Answer(s): (a) 231; (b) 305