Adam has 45 stickers.
After
38 of the green stickers is given away and
another 7 red stickers are bought,
there is an equal number of green and red stickers.
- How many green stickers are there in the end?
- How many less red stickers than green stickers are there at first?
- How many green stickers are given away?
|
Green |
Red |
Before |
8 u |
5 u - 7 |
Change |
- 3 u |
+ 7 |
After |
5 u |
5 u |
(a)
Fraction of the green stickers left
= 1 -
38 =
58 The number of green stickers and red stickers in the end is the same.
Total number of stickers at first
= 8 u + 5 u - 7
= 13 u - 7
13 u - 7 = 45
13 u = 45 + 7
13 u = 52
1 u = 52 ÷ 13 = 4
Number of green stickers in the end
= 5 u
= 5 x 4
= 20
(b)
Number of less red stickers than green stickers at first
= 8 u - (5 u - 7)
= 8 u - 5 u + 7
= 3 u + 7
= 3 x 4 + 7
= 12 + 7
= 19
(c)
Number of green stickers given away
= 3 u
= 3 x 4
= 12
Answer(s): (a) 20; (b) 19; (c) 12