Adam has some red stickers and blue stickers.
If Adam receives another 65 blue stickers,
the red stickers will be 20% as many as the blue stickers.
If Adam receives another 74 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 - 65 |
4 p - 74 |
5 p |
Change |
No change |
+ 65 |
+ 74 |
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 - 65
Scenario 2 Number of red stickers at first = 4 p - 74
Number of blue stickers at first = 5 p
1 u = 4 p - 74 --- (1)
5 u - 65 = 5 p --- (2)
(2)
÷ 51 u - 13 = 1 p
1 u = 1 p + 13 --- (3)
(1) = (3)
4 p - 74 = 1 p + 13
4 p - 1 p = 74 + 13
3 p = 87
1 p = 87 ÷ 3 = 29
Number of red stickers
= 4 p - 74
= 4 x 29 - 74
= 116 - 74
= 42
(b)
Number of blue stickers
= 5 p
= 5 x 29
= 145
Answer(s): (a) 42; (b) 145