Adam has some red stickers and blue stickers.
If Adam gives away 32 red stickers,
the red stickers will be 25% as many as the blue stickers.
If Adam gives away 15 blue 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 + 32 |
4 u |
4 p |
5 p + 15 |
Change |
- 32 |
No change |
No change |
- 15 |
After |
1 u |
4 u |
4 p |
5 p |
(a)
25% =
25100 =
14 80% =
80100 =
45 Scenario 1 Number of red stickers at first = 1 u + 32
Number of blue stickers at first = 4 u
Scenario 2 Number of red stickers at first = 4 p
Number of blue stickers at first = 5 p + 15
1 u + 32 = 4 p --- (1)
4 u = 5 p + 15 --- (2)
(1)
x 4 4 u + 128 = 16 p
4 u = 16 p - 128 --- (3)
(3) = (2)
16 p - 128 = 5 p + 15
16 p - 5 p = 128 + 15
11 p = 143
1 p = 143 ÷ 11 = 13
Number of red stickers
= 4 p
= 4 x 13
= 52
(b)
Number of blue stickers at first
= 5 p + 15
= 5 x 13 + 15
= 65 + 15
= 80
Answer(s): (a) 52; (b) 80