Adam has some red stickers and blue stickers.
If Adam gives away 25 red stickers,
the red stickers will be 20% as many as the blue stickers.
If Adam gives away 84 blue stickers,
the red stickers will be 75% 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 + 25 |
5 u |
3 p |
4 p + 84 |
Change |
- 25 |
No change |
No change |
- 84 |
After |
1 u |
5 u |
3 p |
4 p |
(a)
20% =
20100 =
15 75% =
75100 =
34 Scenario 1 Number of red stickers at first = 1 u + 25
Number of blue stickers at first = 5 u
Scenario 2 Number of red stickers at first = 3 p
Number of blue stickers at first = 4 p + 84
1 u + 25 = 3 p --- (1)
5 u = 4 p + 84 --- (2)
(1)
x 5 5 u + 125 = 15 p
5 u = 15 p - 125 --- (3)
(3) = (2)
15 p - 125 = 4 p + 84
15 p - 4 p = 125 + 84
11 p = 209
1 p = 209 ÷ 11 = 19
Number of red stickers
= 3 p
= 3 x 19
= 57
(b)
Number of blue stickers at first
= 4 p + 84
= 4 x 19 + 84
= 76 + 84
= 160
Answer(s): (a) 57; (b) 160