Adam has some blue stickers and red stickers.
If Adam gives away 31 blue stickers,
the blue stickers will be 20% as many as the red stickers.
If Adam gives away 65 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 + 31 |
5 u |
3 p |
4 p + 65 |
Change |
- 31 |
No change |
No change |
- 65 |
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 + 31
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 + 65
1 u + 31 = 3 p --- (1)
5 u = 4 p + 65 --- (2)
(1)
x 5 5 u + 155 = 15 p
5 u = 15 p - 155 --- (3)
(3) = (2)
15 p - 155 = 4 p + 65
15 p - 4 p = 155 + 65
11 p = 220
1 p = 220 ÷ 11 = 20
Number of blue stickers
= 3 p
= 3 x 20
= 60
(b)
Number of red stickers at first
= 4 p + 65
= 4 x 20 + 65
= 80 + 65
= 145
Answer(s): (a) 60; (b) 145