Adam has 185 stickers.
After
29 of the red stickers is given away and
another 39 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 |
7 u - 39 |
Change |
- 2 u |
+ 39 |
After |
7 u |
7 u |
(a)
Fraction of the red stickers left
= 1 -
29 =
79 The number of red stickers and blue stickers in the end is the same.
Total number of stickers at first
= 9 u + 7 u - 39
= 16 u - 39
16 u - 39 = 185
16 u = 185 + 39
16 u = 224
1 u = 224 ÷ 16 = 14
Number of red stickers in the end
= 7 u
= 7 x 14
= 98
(b)
Number of less blue stickers than red stickers at first
= 9 u - (7 u - 39)
= 9 u - 7 u + 39
= 2 u + 39
= 2 x 14 + 39
= 28 + 39
= 67
(c)
Number of red stickers given away
= 2 u
= 2 x 14
= 28
Answer(s): (a) 98; (b) 67; (c) 28