Adam has 140 stickers.
After
27 of the green stickers is given away and
another 40 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 |
7 u |
5 u - 40 |
Change |
- 2 u |
+ 40 |
After |
5 u |
5 u |
(a)
Fraction of the green stickers left
= 1 -
27 =
57 The number of green stickers and red stickers in the end is the same.
Total number of stickers at first
= 7 u + 5 u - 40
= 12 u - 40
12 u - 40 = 140
12 u = 140 + 40
12 u = 180
1 u = 180 ÷ 12 = 15
Number of green stickers in the end
= 5 u
= 5 x 15
= 75
(b)
Number of less red stickers than green stickers at first
= 7 u - (5 u - 40)
= 7 u - 5 u + 40
= 2 u + 40
= 2 x 15 + 40
= 30 + 40
= 70
(c)
Number of green stickers given away
= 2 u
= 2 x 15
= 30
Answer(s): (a) 75; (b) 70; (c) 30