Adam has 152 stickers.
After
27 of the blue stickers is given away and
another 28 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 |
7 u |
5 u - 28 |
Change |
- 2 u |
+ 28 |
After |
5 u |
5 u |
(a)
Fraction of the blue stickers left
= 1 -
27 =
57 The number of blue stickers and red stickers in the end is the same.
Total number of stickers at first
= 7 u + 5 u - 28
= 12 u - 28
12 u - 28 = 152
12 u = 152 + 28
12 u = 180
1 u = 180 ÷ 12 = 15
Number of blue stickers in the end
= 5 u
= 5 x 15
= 75
(b)
Number of less red stickers than blue stickers at first
= 7 u - (5 u - 28)
= 7 u - 5 u + 28
= 2 u + 28
= 2 x 15 + 28
= 30 + 28
= 58
(c)
Number of blue stickers given away
= 2 u
= 2 x 15
= 30
Answer(s): (a) 75; (b) 58; (c) 30