Adam has some blue stickers and red stickers.
If Adam gives away 47 blue stickers,
the blue stickers will be 20% as many as the red stickers.
If Adam gives away 40 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 + 47 |
5 u |
3 p |
4 p + 40 |
Change |
- 47 |
No change |
No change |
- 40 |
After |
1 u |
5 u |
3 p |
4 p |
(a)
20% =
20100 =
15 75% =
75100 =
34 Scenario 1 Number of blue stickers at first = 1 u + 47
Number of red stickers at first = 5 u
Scenario 2 Number of blue stickers at first = 3 p
Number of red stickers at first = 4 p + 40
1 u + 47 = 3 p --- (1)
5 u = 4 p + 40 --- (2)
(1)
x 5 5 u + 235 = 15 p
5 u = 15 p - 235 --- (3)
(3) = (2)
15 p - 235 = 4 p + 40
15 p - 4 p = 235 + 40
11 p = 275
1 p = 275 ÷ 11 = 25
Number of blue stickers
= 3 p
= 3 x 25
= 75
(b)
Number of red stickers at first
= 4 p + 40
= 4 x 25 + 40
= 100 + 40
= 140
Answer(s): (a) 75; (b) 140