Adam has 140 stickers.
After
49 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 |
9 u |
5 u - 28 |
Change |
- 4 u |
+ 28 |
After |
5 u |
5 u |
(a)
Fraction of the blue stickers left
= 1 -
49 =
59 The number of blue stickers and red stickers in the end is the same.
Total number of stickers at first
= 9 u + 5 u - 28
= 14 u - 28
14 u - 28 = 140
14 u = 140 + 28
14 u = 168
1 u = 168 ÷ 14 = 12
Number of blue stickers in the end
= 5 u
= 5 x 12
= 60
(b)
Number of less red stickers than blue stickers at first
= 9 u - (5 u - 28)
= 9 u - 5 u + 28
= 4 u + 28
= 4 x 12 + 28
= 48 + 28
= 76
(c)
Number of blue stickers given away
= 4 u
= 4 x 12
= 48
Answer(s): (a) 60; (b) 76; (c) 48