Adam has 450 stickers.
After
13 of the red stickers and
20 blue stickers are given away,
there is an equal number of red and blue stickers left.
- How many red stickers are there in the end?
- How many more red stickers than blue stickers are there at first?
- How many red stickers are given away?
|
Red stickers |
Blue stickers |
Total |
Before |
3 u |
2 u + 20 |
450 |
Change |
- 1 u |
- 20 |
|
After |
2 u |
2 u |
|
(a)
Fraction of the red stickers left
= 1 -
13 =
23 Total number of stickers at first
= 3 u + 2 u + 20
= 5 u + 20
5 u + 20 = 450
5 u = 450 - 20
5 u = 430
1 u = 430 ÷ 5 = 86
Number of red stickers in the end
= 2 u
= 2 x 86
= 172
(b)
Number of more red stickers than blue stickers at first
= 3 u - (2 u + 20)
= 3 u - 2 u - 20
= 1 u - 20
= 1 x 86 - 20
= 86 - 20
= 66
(c)
Number of red stickers given away
= 1 u
= 86
Answer(s): (a) 172; (b) 66; (c) 86