Adam has 167 stickers.
After
25 of the blue stickers is given away and
another 25 red stickers are bought,
there is an equal number of blue and red stickers.
- How many blue stickers are there in the end?
- How many less red stickers than blue stickers are there at first?
- How many blue stickers are given away?
|
Blue |
Red |
Before |
5 u |
3 u - 25 |
Change |
- 2 u |
+ 25 |
After |
3 u |
3 u |
(a)
Fraction of the blue stickers left
= 1 -
25 =
35 The number of blue stickers and red stickers in the end is the same.
Total number of stickers at first
= 5 u + 3 u - 25
= 8 u - 25
8 u - 25 = 167
8 u = 167 + 25
8 u = 192
1 u = 192 ÷ 8 = 24
Number of blue stickers in the end
= 3 u
= 3 x 24
= 72
(b)
Number of less red stickers than blue stickers at first
= 5 u - (3 u - 25)
= 5 u - 3 u + 25
= 2 u + 25
= 2 x 24 + 25
= 48 + 25
= 73
(c)
Number of blue stickers given away
= 2 u
= 2 x 24
= 48
Answer(s): (a) 72; (b) 73; (c) 48