Adam has some red stickers and blue stickers.
If Adam receives another 30 blue stickers,
the red stickers will be 20% as many as the blue stickers.
If Adam receives another 75 red stickers,
the red stickers will be 80% as many as the blue stickers.
- How many red stickers are there?
- How many blue stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Red |
Blue |
Red |
Blue |
Before |
1 u |
5 u - 30 |
4 p - 75 |
5 p |
Change |
No change |
+ 30 |
+ 75 |
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 blue stickers at first = 5 u - 30
Scenario 2 Number of red stickers at first = 4 p - 75
Number of blue stickers at first = 5 p
1 u = 4 p - 75 --- (1)
5 u - 30 = 5 p --- (2)
(2)
÷ 51 u - 6 = 1 p
1 u = 1 p + 6 --- (3)
(1) = (3)
4 p - 75 = 1 p + 6
4 p - 1 p = 75 + 6
3 p = 81
1 p = 81 ÷ 3 = 27
Number of red stickers
= 4 p - 75
= 4 x 27 - 75
= 108 - 75
= 33
(b)
Number of blue stickers
= 5 p
= 5 x 27
= 135
Answer(s): (a) 33; (b) 135