Adam has 170 stickers.
After
13 of the blue stickers and
20 red stickers are given away,
there is an equal number of blue and red stickers left.
- How many blue stickers are there in the end?
- How many more blue stickers than red stickers are there at first?
- How many blue stickers are given away?
|
Blue stickers |
Red stickers |
Total |
Before |
3 u |
2 u + 20 |
170 |
Change |
- 1 u |
- 20 |
|
After |
2 u |
2 u |
|
(a)
Fraction of the blue stickers left
= 1 -
13 =
23 Total number of stickers at first
= 3 u + 2 u + 20
= 5 u + 20
5 u + 20 = 170
5 u = 170 - 20
5 u = 150
1 u = 150 ÷ 5 = 30
Number of blue stickers in the end
= 2 u
= 2 x 30
= 60
(b)
Number of more blue stickers than red stickers at first
= 3 u - (2 u + 20)
= 3 u - 2 u - 20
= 1 u - 20
= 1 x 30 - 20
= 30 - 20
= 10
(c)
Number of blue stickers given away
= 1 u
= 30
Answer(s): (a) 60; (b) 10; (c) 30