Adam has some blue stickers and red stickers.
If 153 blue stickers are removed, 70% of the stickers will be red stickers.
If 63 blue stickers are removed, 40% of the stickers will be red stickers.
- How many blue stickers are there?
- How many red stickers are there?
|
Scenario 1 |
Scenario 2 |
|
Blue |
Red |
Blue |
Red |
Before |
6 u + 153 |
14 u |
21 u + 63 |
14 u |
Change |
- 153 |
No change |
- 63 |
No change |
After |
3x2 = 6 u |
7x2 = 14 u |
3x7 = 21 u |
2x7 = 14 u |
(a)
70% =
70100 =
71040% =
40100 =
25Scenario 1 Fraction of the stickers that are blue in the end
= 1 -
710 =
310 Scenario 2
Fraction of the stickers that are blue in the end
= 1 -
25 =
35 The number of red stickers remains unchanged in both scenarios.
LCM of 7 and 2 = 14
6 u + 153 = 21 u + 63
21 u - 6 u = 153 - 63
15 u = 90
1 u = 90 ÷ 15 = 6
Number of blue stickers
= 6 u + 153
= 6 x 6 + 153
= 36 + 153
= 189
(b)
Number of red stickers
= 14 u
= 14 x 6
= 84
Answer(s): (a) 189; (b) 84