Adam has 168 stickers.
After
79 of the red stickers is given away and
another 8 blue stickers are bought,
there is an equal number of red and blue stickers.
- How many red stickers are there in the end?
- How many less blue stickers than red stickers are there at first?
- How many red stickers are given away?
|
Red |
Blue |
Before |
9 u |
2 u - 8 |
Change |
- 7 u |
+ 8 |
After |
2 u |
2 u |
(a)
Fraction of the red stickers left
= 1 -
79 =
29 The number of red stickers and blue stickers in the end is the same.
Total number of stickers at first
= 9 u + 2 u - 8
= 11 u - 8
11 u - 8 = 168
11 u = 168 + 8
11 u = 176
1 u = 176 ÷ 11 = 16
Number of red stickers in the end
= 2 u
= 2 x 16
= 32
(b)
Number of less blue stickers than red stickers at first
= 9 u - (2 u - 8)
= 9 u - 2 u + 8
= 7 u + 8
= 7 x 16 + 8
= 112 + 8
= 120
(c)
Number of red stickers given away
= 7 u
= 7 x 16
= 112
Answer(s): (a) 32; (b) 120; (c) 112