Adam has some blue stickers and red stickers.
If Adam gives away 27 blue stickers,
the blue stickers will be 10% as many as the red stickers.
If Adam gives away 42 red stickers,
the blue stickers will be 75% as many as the red stickers.
- How many blue stickers are there?
- How many red stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Blue |
Red |
Blue |
Red |
Before |
1 u + 27 |
10 u |
3 p |
4 p + 42 |
Change |
- 27 |
No change |
No change |
- 42 |
After |
1 u |
10 u |
3 p |
4 p |
(a)
10% =
10100 =
110 75% =
75100 =
34 Scenario 1 Number of blue stickers at first = 1 u + 27
Number of red stickers at first = 10 u
Scenario 2 Number of blue stickers at first = 3 p
Number of red stickers at first = 4 p + 42
1 u + 27 = 3 p --- (1)
10 u = 4 p + 42 --- (2)
(1)
x 10 10 u + 270 = 30 p
10 u = 30 p - 270 --- (3)
(3) = (2)
30 p - 270 = 4 p + 42
30 p - 4 p = 270 + 42
26 p = 312
1 p = 312 ÷ 26 = 12
Number of blue stickers
= 3 p
= 3 x 12
= 36
(b)
Number of red stickers at first
= 4 p + 42
= 4 x 12 + 42
= 48 + 42
= 90
Answer(s): (a) 36; (b) 90